Develop Reference

An error has occurred during web site deployment in App Service Editor

I made some changes in the QnAMakerBasDialog.cs file, in trying to edit the default threshold. I did not change any other thing. When I tried deploying my changes at first, I was not getting the expected response and so I went back the editor to reverse my changes. It was at this point I started getting this error message.
I need help in reversing all changes if possible but most expecially in getting "test web chart" and all my channels working again.
Please see error message error:
kindly note that I tried this in the kudu console but still got the same error message
\> build.cmd
1 file(s) copied.
Installing Kudu Sync
D:\local\AppData\npm\kudusync -> D:\local\AppData\npm\node_modules\kudusync\bin\kudusync
+ kudusync#0.3.0
added 7 packages from 8 contributors in 3.22s
Handling ASP.NET Core Web Application deployment.
Failed to add 'D:\local\UserProfile\.dotnet\tools' to the PATH environment variable. Add this directory to your PATH to use tools installed with 'dotnet tool install'.
Welcome to .NET Core 3.1!
---------------------
SDK Version: 3.1.301
Telemetry
---------
The .NET Core tools collect usage data in order to help us improve your experience. The data is anonymous. It is collected by Microsoft and shared with the community. You can opt-out of telemetry by setting the DOTNET_CLI_TELEMETRY_OPTOUT environment variable to '1' or 'true' using your favorite shell.
Read more about .NET Core CLI Tools telemetry: https://aka.ms/dotnet-cli-telemetry
----------------
Explore documentation: https://aka.ms/dotnet-docs
Report issues and find source on GitHub: https://github.com/dotnet/core
Find out what's new: https://aka.ms/dotnet-whats-new
Learn about the installed HTTPS developer cert: https://aka.ms/aspnet-core-https
Use 'dotnet --help' to see available commands or visit: https://aka.ms/dotnet-cli-docs
Write your first app: https://aka.ms/first-net-core-app
--------------------------------------------------------------------------------------
Unhandled exception. System.ComponentModel.Win32Exception (5): Access is denied.
at System.Diagnostics.Process.set_PriorityClassCore(ProcessPriorityClass value)
at System.Diagnostics.Process.set_PriorityClass(ProcessPriorityClass value)
at Microsoft.Build.CommandLine.MSBuildApp.Execute(String[] commandLine)
at Microsoft.Build.CommandLine.MSBuildApp.Main(String[] args)
MSBUILD : error MSB1025: An internal failure occurred while running MSBuild.
System.ComponentModel.Win32Exception (5): Access is denied.
at System.Diagnostics.Process.set_PriorityClassCore(ProcessPriorityClass value)
at System.Diagnostics.Process.set_PriorityClass(ProcessPriorityClass value)
at Microsoft.Build.CommandLine.MSBuildApp.Execute(String[] commandLine)
Failed exitCode=-532462766, command=dotnet restore "QnABot.sln"
An error has occurred during web site deployment.

Surprisingly, I also encountered this problem. I also encountered this problem in Buid after modifying the Azure Bot code!
Even with this error, my build is successful

ICU Package installation Linux

When I try to run a c# program on my linux controller I get the following error:
Process terminated. Couldn't find a valid ICU package installed on the system. Set the configuration flag System.Globalization.Invariant to true if you want to run with no globalization support.
at System.Environment.FailFast(System.String)
at System.Globalization.GlobalizationMode.GetGlobalizationInvariantMode()
at System.Globalization.GlobalizationMode..cctor()
at System.Globalization.CultureData.CreateCultureWithInvariantData()
at System.Globalization.CultureData.get_Invariant()
at System.Globalization.CultureInfo..cctor()
at System.StringComparer..cctor()
at System.StringComparer.get_OrdinalIgnoreCase()
at Microsoft.Data.Sqlite.SqliteConnectionStringBuilder..cctor()
I want to install an ICU package to get rid of this error. So I downloaded a package from this site:
Internationnal Components for Unicode
When I installed the package on the controller I still got the message. Is there any proper way to install an ICU package on the linux controller so I can get rid of this message?
P.S. (turning globalization invariant on is not an option because my code (SQL-Server) does not allow it to be on...)

you can disable ICU usage putting this in your .csproj:
<PropertyGroup>
<InvariantGlobalization>true</InvariantGlobalization>
</PropertyGroup>
before running your project, delete manually /bin and /obj

Process terminated. Couldn't find a valid ICU package installed on the system in Asp.Net Core 3 - ubuntu

I am trying to run a Asp.Net Core 3 application in Ubuntu 19.10 thru terminal using dotnet run command but it does not seem to work. I get this error.
Process terminated. Couldn't find a valid ICU package installed on the system.
Set the configuration flag System.Globalization.Invariant to true if you want
to run with no globalization support.
at System.Environment.FailFast(System.String)
at System.Globalization.GlobalizationMode.GetGlobalizationInvariantMode()
at System.Globalization.GlobalizationMode..cctor()
at System.Globalization.CultureData.CreateCultureWithInvariantData()
at System.Globalization.CultureData.get_Invariant()
at System.Globalization.CultureInfo..cctor()
at System.StringComparer..cctor()
at System.StringComparer.get_OrdinalIgnoreCase()
at Microsoft.Extensions.Configuration.ConfigurationProvider..ctor()
at Microsoft.Extensions.Configuration.EnvironmentVariables.EnvironmentVariablesConfigurationSource.Build(Microsoft.Extensions.Configuration.IConfigurationBuilder)
at Microsoft.Extensions.Configuration.ConfigurationBuilder.Build()
at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder..ctor(Microsoft.Extensions.Hosting.IHostBuilder)
at Microsoft.Extensions.Hosting.GenericHostWebHostBuilderExtensions.ConfigureWebHost(Microsoft.Extensions.Hosting.IHostBuilder, System.Action'1<Microsoft.AspNetCore.Hosting.IWebHostBuilder>)
at Microsoft.Extensions.Hosting.GenericHostBuilderExtensions.ConfigureWebHostDefaults(Microsoft.Extensions.Hosting.IHostBuilder, System.Action'1<Microsoft.AspNetCore.Hosting.IWebHostBuilder>)
at WebApplication.Program.CreateHostBuilder(System.String[])
at WebApplication.Program.Main(System.String[])
I installed the dotnet core sdk using the ubuntu store and after that I also installed Rider IDE.
The weird thing here is that when I run the app using Rider it runs fine, the only issue is using terminal dotnet core commands.
Does anybody know what might be the issue ?
The application is created using Rider. I don't think that this plays a role but just as a side fact.
I know there are also other ways to install dotnet core in ubuntu but since the sdk is available in the ubuntu story I thought it should work out of the box and of course its an easier choice.
Also tried this one but does not seem to work for me. Still the same issue happens after running the commands.

The alternative solution as described in Microsoft documentation is to set environment variable before running your app
export DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1

If you want to run with no globalization support, you need to get "System.Globalization.Invariant": true into your published output AppName.runtimeconfig.json file as shown in the example below:
{
"runtimeOptions": {
"tfm": "netcoreapp3.0",
"configProperties": {
"System.GC.Server": true,
"System.Globalization.Invariant": true
}
}
}
You can add it manually every time you deploy by adding or updating the AppName.runtimeconfig.json file. Better yet, add it once to a runtimeconfig.template.json file like this:
{
"configProperties": {
"System.Globalization.Invariant": true
}
}
Make sure that runtimeconfig.template.json is included in build/publish.

It seem the package libicu63 will provide the ico support for dotnet on Linux, at least on Debian'ish distros.
Update:
And it seems it's "missing" when doing a small installing of Debian (i.e. deselect all applications/system-options in the installation program, except for SSH server)

The trick around it on Ubuntu 20.04 based on this thread https://github.com/dotnet/core/issues/2186#issuecomment-671105420
$export DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1

Yes. When installing Github action in Debian. It is also required.
As the response from MrCalvin,
sudo apt-get update && sudo apt-get install -qqq libicu63 resolve my issue.

edit your .bashrc file by adding the following line, e.g.:
nano ~/.bashrc
add
export DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1
Ctrl+o, Ctrl+x
restart terminal and run pwsh again

I had this issue while trying to run Umbraco version 9.2.0. Fiddling with System.Globalization.Invariant was not a good solution as it broke globalization in the backoffice. This issue has been solved in v9.4: https://github.com/umbraco/Umbraco-CMS/pull/11961
I didn't want to upgrade my Umbraco version to solve this, so I just copied the change in that commit to my project.
Simply go into the .csproj file of your web project and change the ICU package reference lines to:
<!-- Force windows to use ICU. Otherwise Windows 10 2019H1+ will do it, but older windows 10 and most if not all winodws servers will run NLS -->
<ItemGroup>
<PackageReference Include="Microsoft.ICU.ICU4C.Runtime" Version="68.2.0.9" />
<RuntimeHostConfigurationOption
Condition="$(RuntimeIdentifier.StartsWith('linux')) Or $(RuntimeIdentifier.StartsWith('win')) Or ('$(RuntimeIdentifier)' == '' And !$([MSBuild]::IsOSPlatform('osx')))"
Include="System.Globalization.AppLocalIcu"
Value="68.2.0.9" />
</ItemGroup>

In my case, I followed the Windows documentation to install SDK dependencies and Runtime, watch out for the corresponding version to each Linux distribution to avoid compatibility issues.

This helped me override the default ICU version to the one that's installed on the machine running arch linux.
export CLR_ICU_VERSION_OVERRIDE=$(pacman -Q icu | awk '{split($0,a," ");print a[2]}' | awk '{split($0,a,"-");print a[1]}')

Deploy a C# Stateful Service Fabric application from Visual Studio to Linux

EDIT 04/06/18 => Updated question with last status
So I have this working .Net 4.6 Stateful Service that currently run on my Windows Service Fabric cluster deployed on Azure.
Starting from 09/2017, I should be able to move to Linux: https://blogs.msdn.microsoft.com/azureservicefabric/2017/09/25/service-fabric-6-0-release/
So I'm trying to deploy it on Linux so I can save costs.
First things first, I've migrated all my code from .Net 4.6 to .Net Core 2.0. Now I can compile my binaries without issues. I've basically created new .Net Core projects and then moved all my source code from .Net 4.6 projects to the new .Net Core ones.
Then I've updated my Service Fabric application. I removed my previous SF services from my sfproj, then I've added my new .Net Core ones.
Looks like there is a warning (nothing on the output window though), but it's here anyway if I try to create a new empty Statful service using .Net core 2.0 through the template provided by Service Fabric Tools 2.0 (beta):
So I'm going to live with it.
On my dev machine, I've modified the 2 csproj projects that contain my Stateful services so they can run locally as Windows executables. I've used the win7-x64 runtimeIdentifier.
Running my SF cluster locally on my Windows machine is fine.
Then I've slightly changed the previous csproj files for Linux. I used the ubuntu.16.10-x64 runtimeIdentifier.
Also I've changed the ServiceManifest.xml file to target the linux-compatible binary:
<!-- Code package is your service executable. -->
<CodePackage Name="Code" Version="1.9.6">
<EntryPoint>
<ExeHost>
<Program>entryPoint.sh</Program>
</ExeHost>
</EntryPoint>
</CodePackage>
entryPoint.sh is a basic script that eventually executes:
dotnet $DIR/MyService.dll
Then I've successfully deployed to my secured SF Linux cluster from Visual Studio. Unfortunately I have the following errors for both my stateful services:
Error event: SourceId='System.Hosting',
Property='CodePackageActivation:Code:EntryPoint'. There was an error
during CodePackage activation.The service host terminated with exit
code:134
Looks like my binary crashes when starting. So here are my questions:
Is the approach right to deploy a C# .Net Core SF stateful service on Linux from Visual Studio?
EDIT: looking inside the LinuxsyslogVer2v0 table, I get the following error:
starthost.sh[100041]: Unhandled Exception:
System.IO.FileLoadException: Could not load file or assembly
'System.Threading.Thread, Version=4.1.0.0, Culture=neutral,
PublicKeyToken=b03f5f7f11d50a3a'. The located assembly's manifest
definition does not match the assembly reference. (Exception from
HRESULT: 0x80131040)
I found the following bug report: https://github.com/dotnet/sdk/issues/1502
Unfortunately, I still get the error without using MSBuild (using dotnet deploy).
EDIT: further clarification:
My boss want me to run on Linux because starting from D1v2 machines, it's half the price compared to Windows machines (no license etc.)
My .NET Core 2.0 services successfully run on Windows. So the .NET Core port should be fine.

So, this was a real pain in the ass to get it working properly. But it works. Well, kind of.
First, Reliable Services are still in preview on Linux: https://github.com/Microsoft/service-fabric/issues/71
Full Linux support should come very soon (actually it should be available already according to the previous link...).
Now for the details about how to procede, here is some information to help others, because there is just nothing about that on Microsoft documentation and I literally lost 3 days trying to make it work.
1. Do use .NET Core 2.0 for your projects.
It is supported on Linux. On preview for now, but it works.
2. Do use the right RID for your projects.
As of today (April 2018), the right RID to use is ubuntu.16.04-x64.
Edit the csproj files of your Reliable Service projects and set the RID like this:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>netcoreapp2.0</TargetFramework>
<IsServiceFabricServiceProject>True</IsServiceFabricServiceProject>
<RuntimeIdentifier>ubuntu.16.04-x64</RuntimeIdentifier>
<Platforms>AnyCPU;x64</Platforms>
</PropertyGroup>
The fun part is, you should be able to provide multiple RIDs using the RuntimeIdentifiers parameter (with a S at the end) like that:
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>netcoreapp2.0</TargetFramework>
<IsServiceFabricServiceProject>True</IsServiceFabricServiceProject>
<RuntimeIdentifiers>win7x64;ubuntu.16.04-x64</RuntimeIdentifiers>
<Platforms>AnyCPU;x64</Platforms>
</PropertyGroup>
So you could build Windows binaries and Linux binaries at the same time.
But it simply doesn't work. When building the project from Visual Studio, I end up with the following directory only:
bin/Debug/netcoreapp2.0/
Only DLLs, no valid entry point. No win7-x64 folder, no ubuntu.16.04-x64, no nothing.
This is a bug, supposed to be fixed, but it's not (I use Visual Studio 15.6.2 all up-to-date as of today). See https://github.com/dotnet/core/issues/1039
3. You need a valid Entry Point for your service.
On Windows it's an executable file (*.exe). On Linux it's not. I ended up getting the Linux C# example and copied/pasted the entry point. https://learn.microsoft.com/en-us/azure/service-fabric/service-fabric-create-your-first-linux-application-with-csharp
So basically I now have on my ServiceManifest.xml file of each Reliable Service the following EntryPoint :
<?xml version="1.0" encoding="utf-8"?>
<ServiceManifest Name="XXXX"
Version="1.0.0"
xmlns="http://schemas.microsoft.com/2011/01/fabric"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<ServiceTypes>
<!-- This is the name of your ServiceType.
This name must match the string used in RegisterServiceType call in Program.cs. -->
<StatefulServiceType ServiceTypeName="YYY" HasPersistedState="true" />
</ServiceTypes>
<!-- Code package is your service executable. -->
<CodePackage Name="Code" Version="1.0.0">
<EntryPoint>
<ExeHost>
<Program>entryPoint.sh</Program>
</ExeHost>
</EntryPoint>
</CodePackage>
entryPoint.sh is as follows:
#!/usr/bin/env bash
check_errs()
{
# Function. Parameter 1 is the return code
if [ "${1}" -ne "0" ]; then
# make our script exit with the right error code.
exit ${1}
fi
}
DIR=`dirname $0`
echo 0x3f > /proc/self/coredump_filter
source $DIR/dotnet-include.sh
dotnet $DIR/NAME_OF_YOUR_SERVICE_DLL.dll $#
check_errs $?
dotnet-include.sh is as follows:
#!/bin/bash
. /etc/os-release
linuxDistrib=$ID
if [ $linuxDistrib = "rhel" ]; then
source scl_source enable rh-dotnet20
exitCode=$?
if [ $exitCode != 0 ]; then
echo "Failed: source scl_source enable rh-dotnet20 : ExitCode: $exitCode"
exit $exitCode
fi
fi
Both are inside the PackageRoot folder. I specified for both their properties so the Build Action is "Content" and the Copy to Output Directory is "Copy always".
4. Do NOT build using MSBuild !!
Yeah it is supposed to build Linux packages too, or at least it seems so, because MSBuild is able to produce the following files when you right click on your project and click "Build":
Don't trust the apparent success of the operation, it will miserably FAIL to properly execute when deployed. Some *.so files missing and other issues. MSBuild is buggy as hell and misbehaves regarding dependencies.
See for instance this bug report: https://github.com/dotnet/sdk/issues/1502
Still not fixed after almost a year...
Or https://github.com/dotnet/core/issues/977 (got this one, too).
5. Do write some PowerShell script to build the stuff by yourself.
I ended up reinventing the wheel using the following script to build my package:
# Creating binaries for service 1
cd DIRECTORY_OF_MY_SERVICE_1
dotnet publish -c Release -r ubuntu.16.04-x64
# Creating binaries for service 2
cd ..\DIRECTORY_OF_MY_SERVICE_2
dotnet publish -c Release -r ubuntu.16.04-x64
# Creating binaries for service 3
cd ..\DIRECTORY_OF_MY_SERVICE_3
dotnet publish -c Release -r ubuntu.16.04-x64
# Copying ApplicationManifest.xml
cd ..
mkdir PKG\ServiceFabricApplication
echo F|xcopy "ServiceFabricApplication\ApplicationPackageRoot\ApplicationManifest.xml" "PKG\ServiceFabricApplication\ApplicationManifest.xml" /sy
# Copying Service1 files
mkdir "PKG\ServiceFabricApplication\Service1Pkg"
mkdir "PKG\ServiceFabricApplication\Service1Pkg\Code"
xcopy "Service1\PackageRoot\*" "PKG\ServiceFabricApplication\Service1Pkg" /sy /D
xcopy "Service1\bin\Release\netcoreapp2.0\ubuntu.16.04-x64\publish\*" "PKG\ServiceFabricApplication\Service1Pkg\Code" /sy
# Copying Service2 files
mkdir "PKG\ServiceFabricApplication\Service2Pkg"
mkdir "PKG\ServiceFabricApplication\Service2Pkg\Code"
xcopy "Service2\PackageRoot\*" "PKG\ServiceFabricApplication\Service2Pkg" /sy /D
xcopy "Service2\bin\Release\netcoreapp2.0\ubuntu.16.04-x64\publish\*" "PKG\ServiceFabricApplication\Service2Pkg\Code" /sy
# Copying Service3 files
mkdir "PKG\ServiceFabricApplication\Service3Pkg"
mkdir "PKG\ServiceFabricApplication\Service3Pkg\Code"
xcopy "Service3\PackageRoot\*" "PKG\ServiceFabricApplication\Service3Pkg" /sy /D
xcopy "Service3\bin\Release\netcoreapp2.0\ubuntu.16.04-x64\publish\*" "PKG\ServiceFabricApplication\Service3Pkg\Code" /sy
# Compresses the package
Write-host "Compressing package..."
Copy-ServiceFabricApplicationPackage -ApplicationPackagePath .\PKG\ServiceFabricApplication -CompressPackage -SkipCopy
sfproj file is a Visual Studio / MSBuild related project, so you need to build everything by yourself.
The script above produces the same content as the pkg folder created by MSBuild when building your sfproj using Visual Studio. It copies everything on a PKG folder at the root of your solution.
The package structure is detailed here: https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/service-fabric/service-fabric-package-apps.md
6. Now it's time to deploy!
At this point I didn't trusted Visual Studio anymore, so I built my own PowerShell script:
. .\ServiceFabricApplication\Scripts\Deploy-FabricApplication.ps1 -ApplicationPackagePath '.\PKG\ServiceFabricApplication' -PublishProfileFile '.\ServiceFabricApplication\PublishProfiles\Cloud.xml' -DeployOnly:$false -ApplicationParameter:#{} -UnregisterUnusedApplicationVersionsAfterUpgrade $false -OverrideUpgradeBehavior 'None' -OverwriteBehavior 'SameAppTypeAndVersion' -SkipPackageValidation:$false -ErrorAction Stop
It reuses the Deploy-FabricApplication.ps1 script provided by the Service Fabric project template inside the sfproj project. This script parses the Cloud.xml PublishProfile and deploys to your service fabric cluster.
So you specifies the rights values on both PublishProfiles/Cloud.xml and ApplicationParameters/Cloud.xml then execute the script.
It only works if you have the certificate used to secure the cluster installed on your machine, of course.
Do note the first dot '.' is important, because if you don't use it, you'll have the following error:
Get-ServiceFabricClusterManifest : Cluster connection instance is null
See https://stackoverflow.com/a/38104087/870604
Oh, and as there are bugs on the Service Fabric SDK too, you might want to shutdown your local SF cluster too...
https://github.com/Azure/service-fabric-issues/issues/821
7. Now it's time for another deception.
It simply doesn't work, the service crashes on startup. After searching hours inside the LinuxsyslogVer2v0 Azure Storage table (the log table for Linux, located in one of the two Azure Storage Accounts created automatically with the SF cluster), I found that Microsoft own Nuget Packages were buggy too.
Specifically, the Nuget package Microsoft.Azure.Devices doesn't work on version 1.6.0. An issue with a reference of a dll not found or whatever. I rollbacked to a previous version, namely 1.5.1, and it was fixed.
At this point I didn't had anymore energy to create another Github issue about that. Sorry MS, I'm not your QA team, I'm getting tired.
8. Build again using the first PowerShell script, deploy using the second PowerShell script, and you're done.
You've finally deployed C# Reliable Services using .NET Core 2.0 from Visual Studio (kind of, as it's buggy and I used PowerShell) on Windows to a Linux SF Cluster.
Now I still have issues with my ASP.NET Core service, but it will be a story for another day.
Conclusion: TL;DR
The whole thing is a mess. Bugs everywhere. In the SDK, in the tools, in some of Microsoft Nuget Packages. Awful experience. But it is supported (in preview for now) and you can make it work. Hope this post will help...

I was having similar issues, but I believe this is the issue:
In this release, .NET Core 2.0 services are only supported on Service Fabric for Windows. Full cross-platform support for .NET Core 2.0 services on Windows and Linux is coming soon.
From the Service Fabric 6.1 Release Notes
So no Linux as long as you are targeting .net core 2.0.

I have success deploy to Linux service fabric with this help
Open all the service .csproj files and update the RuntimeIdentifier as shown below
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>netcoreapp2.0</TargetFramework>
<IsServiceFabricServiceProject>True</IsServiceFabricServiceProject>
<RuntimeIdentifier>linux-x64</RuntimeIdentifier>
</PropertyGroup>
Update the ServiceManifest.xml to remove .exe extension as shown below
<CodePackage Name="Code" Version="1.0.0">
<EntryPoint>
<ExeHost>
<Program>Web1</Program>
</ExeHost>
</EntryPoint>
</CodePackage>
See https://blogs.msdn.microsoft.com/premier_developer/2018/05/27/running-net-core-2-0-applications-in-a-linux-service-fabric-cluster-on-azure/
*Visual Studio 15.7.3

How should I be using Npgsql in Appharbor?

I've developed a quick and simple app on my local machine using SQLite to get started. Now that I'm in the middle of working out how to upload to AppHarbor, I'm a bit stuck on getting the link to ElephantSQL to work.
I used the Application PostgreSQL Sample Application to determine that I needed to use the PostgreSQLConfiguration class for my FluentNHibernate configuration and install the Npgsql package to my solution (I got version 2.0.12.1).
When I push the code up to AppHarbor, it builds and deploys happily. When the server starts to spin up the AppDomain, it throws the error Could not load file or assembly 'policy.2.0.Npgsql' or one of its dependencies. Modules which are not in the manifest were streamed in. (Exception from HRESULT: 0x80131043). This isn't logged in the Errors section of the AppHarbor dashboard (perhaps this is a missing feature or a bug?) so I had to turn off CustomErrors to figure out what was going on.
What have I missed?
Additional - I tried downgrading to package version 2.0.11. This did not include the policy.2.0.Npgsql.dll file and when trying to load the app, it fails with the error Unable to find the requested .Net Framework Data Provider. It may not be installed..

I got it working by going down to version 2.0.11 and made sure that the DbProviderFactories configuration section had the correct version number in the type attribute.
<DbProviderFactories>
<add name="Npgsql Data Provider" invariant="Npgsql" description=".Net Framework Data Provider for PostgreSQL Server" type="Npgsql.NpgsqlFactory, Npgsql, Version=2.0.11.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7" />
</DbProviderFactories>

I was running npgsql 2.0.13 beta (December 2013) on AppHarbor and was getting hosed by this issue for a little while, till I discovered that it's not needed if you're running the latest assembly and don't care about bindingRedirects - it's a dll generated by the .net AL.exe/assembly linker tool to roll up the contents of the policy.2.0.Npgsql.config file (check out https://github.com/npgsql/Npgsql/blob/master/src/policyFileBuild.bat to see how that's compiled).
MY CONFIGURATION:
VS2012
.net 4.5
MVC4
Entity Framework 6 (installed via nuget package restore)
npgsql - 2.0.13.91 (installed via nuget package restore)
THE HACKY FIX:
By Deleting it from the build as a post build event (Project Menu --> Properties --> Build Events --> Post Event Command Line), you can bypass the error (which I don't know why doesn't work on AppHarbor).
So add this nonsense:
del $(TargetDir)policy.2.0.Npgsql.dll /F
del $(TargetDir)policy.2.0.Npgsql.config /F
dir $(TargetDir)
del $(TargetDir)_PublishedWebsites\<appname/>\bin\policy.2.0.Npgsql.dll
del $(TargetDir)_PublishedWebsites\<appname/>\bin\policy.2.0.Npgsql.config
dir $(TargetDir)_PublishedWebsites\<appname/>\bin\
This is probably over-kill, but note that the dir dos command statement gives you feedback on the contents of your directories to make sure the files have actually been deleted. This is viewable from Show Log of build activities in AppHarbor.
Regarding the 2 sets of deletes on dll and config from that god awful msbuild packaging routine (/output directory and the /output/_PublishedWebsites) - IMHO - it's better to be thorough if you're killing stuff, but it may be sufficient to simply delete only from _publishedwebsites...
When it gets built in AppHarbor, this will chuck it from the targeted deployment. You might have to wait for a few minutes for the deploy to complete, but it's absence from the deploy will unblock you.

I think this nuget package is missing the policy.2.0.Npgsql.dll file. Can you install the package for 2.0.12 version from official nuget Npgsql package? It has the missing file.
I hope it helps.