Develop Reference

Weird Error Upgrading ASP.NET MVC from 4 to 5

I'm converting my project from MVC 4 to MVC 5 (and .Net 4 to .Net 4.5.2, which is the real driver of the changes.)
When I run one of my pages I get this error (blank space added by me for easier reading)
[A]System.Web.WebPages.Razor.Configuration.HostSection cannot be cast
to [B]System.Web.WebPages.Razor.Configuration.HostSection.
Type A originates from 'System.Web.WebPages.Razor, Version=1.0.0.0,
Culture=neutral, PublicKeyToken=31bf3856ad364e35' in the context
'Default' at location
'C:\windows\Microsoft.Net\assembly\GAC_MSIL\System.Web.WebPages.Razor\v4.0_1.0.0.0__31bf3856ad364e35\System.Web.WebPages.Razor.dll'.
Type B originates from 'System.Web.WebPages.Razor, Version=3.0.0.0,
Culture=neutral, PublicKeyToken=31bf3856ad364e35' in the context
'Default' at location
'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET
Files\studentportal3g\2204bad2\aece9b3b\assembly\dl3\ad80387c\91adbf51_fc73d101\System.Web.WebPages.Razor.dll'.
When I first saw this is though, Ah easy! Not so much :)
I've gone over every project and made sure it's version is upgraded to MVC 5 which has the 3.0.0.0 version of System.Web.WebPages.Razor.dll.
Clean rebuild, still get the error. No problem , I'll delete the cached temp files.
Clean rebuild, still get the problem. I go back, manually check each version of System.Web.WebPages.Razor.dll, in the references of each project that has a reference to it. I check my folder where I copy dlls to make references to them manually, it's not there.
If my solution doesn't' contain a copy of the DLL or a reference to the DLL, and I've manually deleted the cache folders in 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET
Files\studentportal3g...
Where is the old bad dll coming from? How do I fix this error? How do I prevent it happening again?
Thanks,
Eric-

Visual Studio is a great tool, but it doesn't always make the right choices when it comes to upgrading dependencies, nor does it support every possible option available in MSBuild. Whenever you find yourself in a bind such as this you should manually review and (if necessary) edit your .csproj file in order to resolve it.
The problem isn't that your file exists in the GAC or that it has not been installed by NuGet, the issue is most likely that one of your project files still has a reference to the old version of System.Web.WebPages.Razor version 1.0.0.0, and you need to find all references to it and change them to 3.0.0.0 accordingly.
Right-click on your project node in Solution Explorer and click Unload Project.
Right-click the project node again and click Edit <projectName>.csproj.
Search the file for references to System.Web.WebPages.Razor and update the version and the HintPath accordingly (as shown below). Make sure the HintPath you use actually points to an existing file.
Repeat these steps for all dependent projects in the solution (and any that are in DLLs that are not part of the solution).
Old Reference
<Reference Include="System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
<Private>True</Private>
<HintPath>..\packages\Microsoft.AspNet.WebPages.1.0.20105.408\lib\net40\System.Web.WebPages.Razor.dll</HintPath>
</Reference>
Updated Reference
<Reference Include="System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
<Private>True</Private>
<HintPath>..\packages\Microsoft.AspNet.WebPages.3.0.0\lib\net45\System.Web.WebPages.Razor.dll</HintPath>
</Reference>
You should also go through the web.config and /Views/web.config files to ensure that they are not referencing any old versions of this assembly.
NOTE: If the above instructions don't solve your issue, the issue likely is outside of your solution. Most likely there is a 3rd party library that is referencing the old version of the file somewhere. If so, you could attempt to get an updated version of the DLL.
You may also want to check out this question.

It looks like the old DLL is in the Global Assembly Cache (GAC). The GAC is a place where you can store assemblies that can be referenced from several applications on the machine. Click here to read more about GAC.
Use the tool gacutil to update the assembly in the GAC.
The tool is located somewhere under "Microsoft SDKs" folder in Program Files. For me, it was located in
C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.6.1 Tools\
Open cmd and navigate to the place where gacutil i stored. Then use it like this:
gacutil.exe -i [path to your assebly] -f.
The -i parameter is for indicating where your assembly is located. The -f parameter is used to force an update of the assembly, if it was already there.
Example
Say your DLL is located in
C:\temp\System.Web.WebPages.Razor.dll
Then you would run gacutil.exe -i "C:\temp\System.Web.WebPages.Razor.dll" -f

Newtonsoft.Json.dll being copied from wrong location in the build server

I got some strange issue here, have a software that build normally in Visual Studio, all references where added using NuGet, and the Newtonsoft.Json.dll is in the packages folder and also the reference points to that folder.
When building in the build server, we notice test failures and going further we found that the Newtonsoft.Json.dll copyed in fact was the wrong one, from Blend folder.
From build log:
Copying file from "D:\APPS\Microsoft Visual Studio
12.0\Blend\Newtonsoft.Json.dll" to "D:\TB\2\PLWRO-WebPP\WebPP-Main-Dev-CI\bin\Newtonsoft.Json.dll".
To solve it I renamed Newtonsoft.Json.dll from blend folder for another thing, and then the build got to work normally as expected.
My question is, WHYYY?!?!? Seems that the build is looking for references before in the Blend folder and not in the set location in the hint path - see below.
<Reference Include="Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
<SpecificVersion>False</SpecificVersion>
<HintPath>..\..\packages\Newtonsoft.Json.7.0.1\lib\net45\Newtonsoft.Json.dll</HintPath>
</Reference>

You could try adding the <private>true</private> element after your HintPath element. This should force the copy to the local directory.
The other part that is interesting, you are looking for an old version (v4.5.0.0) whilst referencing a new version (7.0.1) in your packages.
In Visual Studio, you could try asking Nuget to update the reference to 7.x for this library, and then see if that helps MSBuild pull the library from a more specific location.

Strange Microsoft.Owin DLL issue and Nuget

So I cleaned up some DLL references in an ASP.NET MVC project, I deleted the DLLs in the bin and updated source control to remove the DLLs from source control. I copy all the references to bin on build now, the right way. But when I run localhost I get the error:
Could not load type 'Microsoft.Owin.Security.AuthenticationDescription' from assembly 'Microsoft.Owin, Version=2.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.
So I started comparing DLLs on the server (where the website is working), to my local bin directory. If I copy and replace Microsoft.Own from the server and overwrite my local version, the website works again, error gone.
The thing is the versions of the DLLs are exactly the same, see the following screen shot:
On the left is my local copy, and on the right is the version from the server.
If I look at my References for the ASP.NET MVC Website, I see that Microsoft.Own is located at:
..\packages\Microsoft.Owin.2.1.0\lib**net40**\Microsoft.Owin.dll
And Copy Local is set to True, see screen shot:
So next I deleted the reference for Microsoft.Owin.2.1.0 and tried to readd using the net45 version of Microsoft.Owin.dll instead. So I browsed to ..\packages\Microsoft.Owin.2.1.0\lib**net45**\Microsoft.Owin.dll
But when I went to check the Properties for Microsoft.Owin, under References, the path was still
..\packages\Microsoft.Owin.2.1.0\lib**net40**\Microsoft.Owin.dll
So I then went to my csproj file and saw the following entry:
<Reference Include="Microsoft.Owin.Security, Version=2.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
<SpecificVersion>False</SpecificVersion>
<HintPath>..\packages\Microsoft.Owin.Security.2.1.0\lib\net45\Microsoft.Owin.Security.dll</HintPath>
</Reference>
And in my web.config my targetFramework is 4.5:
<compilation debug="true" targetFramework="4.5">
So finally, I copied and pasted the Microsoft.Owin.dll on the server, that works to
..\packages\Microsoft.Owin.2.1.0\lib**net40**\Microsoft.Owin.dll and ..\packages\Microsoft.Owin.2.1.0\lib**net45**\Microsoft.Owin.dll
To overwrite the package DLL being copied when I Rebuild and STILL I get the error:
Could not load type 'Microsoft.Owin.Security.AuthenticationDescription' from assembly 'Microsoft.Owin, Version=2.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.
Again, if I copy the Microsoft.Owin.dll that is the same version as my local copy, and overwrite my local copy of Microsoft.Owin.dll in the bin, my ASP.NET MVC starts working again, until I build again that is of course.

First check both dll size is same?If size is different then dll are different.
Follow following steps.
Open the project
Remove dll.
Build project now. You will get error.
Close project
Open project again
Don't build project
Clean solution
Add dll and reference
Build project
You will get success

It is possible that some assembly file in "bin" directory which is depended on the error loading assembly.So you should check the project references and clean "bin" directory.

Annoying log4net assemly reference issue in vs 2012

Getting following build error.
Error 15 Unknown build error, 'Could not load file or assembly
'log4net, Version=1.2.11.0, Culture=neutral,
PublicKeyToken=669e0ddf0bb1aa2a' or one of its dependencies. The
located assembly's manifest definition does not match the assembly
reference. (Exception from HRESULT: 0x80131040)'
I dont quite get whats going on.
I tried using GUI for references, it didn't help. Spent 1.5 hours on this already and issue is still present.
I go directly to project file now and the only reference to log4net there is the following:
<Reference Include="log4net, Version=1.2.12.0, Culture=neutral, PublicKeyToken=1b44e1d426115821, processorArchitecture=MSIL">
<SpecificVersion>False</SpecificVersion>
<HintPath>..\..\ExternalDlls\.NET 4.0\log4net.dll</HintPath>
</Reference>
I still get this error. Why does it even mention V1.2.11?
Thanks in advance

Okay got build working finally.
I went through all other projects and did Resharper - Remove unused references action.
After it was done, project started to build.

Can you check what version actually exists in the Path ....\ExternalDlls.NET 4.0\log4net.dll mentioned and see what version is present in GAC.
Remove the version in GAC, remove the below reference the from project file and add it again from the ExternalDlls folder
<Reference Include="log4net, Version=1.2.12.0, Culture=neutral, PublicKeyToken=1b44e1d426115821, processorArchitecture=MSIL">
<SpecificVersion>False</SpecificVersion>
<HintPath>..\..\ExternalDlls\.NET 4.0\log4net.dll</HintPath>
</Reference>

If you are creating a nuget package that is referencing log4net make sure your nuspec file is specifying the correct version of log4net (this is the problem I ran into after log4net released the new build). And make sure that if you don't want the latest version of log4net you encapsulate your version with "[" and "]" so that it doesn't get the latest. See this.. http://docs.nuget.org/docs/reference/versioning#Specifying_Version_Ranges_in_.nuspec_Files
Hope this helps someone.

I am facing this issue today. To solve this problem I deleted log4net.dll file reference from Bin Folder through visual studio. and rebuild the website.
It automatically picks up log4net dll. This solved problem. Reason for this issue was Reference bind through visual studio may not be upto date with the actual file version.

Visual studio 2012 project - Not able to load 'Newtonsoft.Json'

On running a windows phone project in VS 2012, I was getting this error:
{System.IO.FileNotFoundException: Could not load file or assembly 'Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The system cannot find the file specified.
File name: 'Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed'
at MobileConnection.SSCClient.SSCConnection.GetHostNameAndPort()
at MobileConnection.SSCClient.SSCConnection.InitializeSSCConnection(Boolean runningState)}
The corresponding entries in .csproj file is:
<Reference Include="Newtonsoft.Json">
<HintPath>..\packages\Newtonsoft.Json.4.5.11\lib\sl4-windowsphone71\Newtonsoft.Json.dll</HintPath>
</Reference>
And, in packages.config:
<package id="Newtonsoft.Json" version="4.5.11" targetFramework="wp80" />
I debugged it for a while, re-installed the newtonsoft.json package through nuget.
But the solution that worked for me is setting the 'private' property to 'True'.
Updated entry in .csproj file:
<Reference Include="Newtonsoft.Json">
<HintPath>..\packages\Newtonsoft.Json.4.5.11\lib\sl4-windowsphone71\Newtonsoft.Json.dll</HintPath>
<Private>True</Private>
</Reference>
I am not able to understand how it worked or what the issue was. The description on msdn documentation didn't help much either http://msdn.microsoft.com/en-us/library/vstudio/bb629388.aspx.

When running the program, it pulls in dlls from the output directory. Originally, Newtonsoft.Json wasn't being copied to the output directory, but by specifying Private to True, you told Visual Studio to copy the Newtonsoft.Json dll to the output folder along with your program.
For completeness, the documentation on Private:
Optional boolean. Specifies whether the reference should be copied to the output folder. This attribute matches the Copy Local property of the reference that's in the Visual Studio IDE.