Develop Reference

Unity solution not compatible with visual studio

Since updating to the most recent version of Unity 5.4.0f3, whenever I doubleclick on a script, it launches both Visual Studio and Monodevelop, but I get an error saying that the this version of VS (Community 2015) is unable to open my project. Monodevelop displays it's own, somewhat less clear error message. Please see the screen shots below.
I can still manually open my script using Visual Studio's file menu, but the intellisense code completion no longer works. Anyone know how to fix this? I have Visual Studio's Tools for Unity installed.

I was having similar issues when doing a clean download of an existing Unity project onto a fresh install of Visual Studio Community 2019.
In the end the issue for me was that, although the correct version of VS Tools for Unity was installed, it was 'Disabled' by default in VS's Manage Extensions dialog (Extensions -> Manage Extensions). Just had to click 'Enable', restart Visual Studio, and all worked as expected again.

Turns out it was an issue with my existing install of Visual Studio Tools for Unity (VSTU).
I found a thread where users had experienced similar problems due to an unsupported version of VSTU running on Unity5.2 and beyond. Unity 5.2+ requires VSTU 2.1 or later for VS to work correctly with Unity, more information for anyone interested is available in the documentation here.
I had VSTU 2.3 installed, but removing and reinstalling VSTU resolved the issue, so there must have been a problem with my install. If anyone else has this or a similar issue you can download the latest installer for VSTU here. Thanks to all who chimed in your responses helped me look in the right place!

Please try following steps:
Delete old *.csproj and *.sln files on project's root folder
Check "Edit > Preferences > External Tools" and make sure you've selected "Visual Studio"
Re-open solution by "Assets > Open C# Project" menu

For me it was enough to right click the solution in Solution Explorer and run "Resolve errors".

I will complete what is said above. I experienced this issue today and it took me a while. In my case it was relative to a new install of the Unity Editor.
For some unknown reason the unity tool used on VS (intellisense) was uninstalled. I had to reinstall this : open Visual Studio Installer, select your project and reach the Gaming section where reside the tool for Unity.

The extension "Visual Studio 2019 Tools for Unity" seems no longer available for download via the extension manager. Luckily I recalled that I saw some game development features in the Visual Studio installer, so I picked that one:
It works for VS 2019 (16.11.11) and VS 2022 (17.2.0 Preview 1).

Visual Studio 2015 just debug once, then i have to restart VS

I'm a PHP developer, but recently I have to work with Visual Studio in a C# application. I don't know much about C#, just had a few experiences with it, and the problem is when I try to run/debug my code it works only for the first time. If I change ANY piece of code anywhere in the code the project won't launch anymore, all it does when I click "Debug" is open Google Chrome for me and there it hangs awaiting for "localhost" forever... This issue is driving me nuts, I can't program well if I have to restart Visual Studio whenever I change some code.
I have tried a lot of things that I found here and on Google, but nothing helped. I have fully repaired VS 2015, didn't work. Then I reinstalled it and still not working.

Visual Studio 2015 Community Edition failed to download new license

I recently uninstalled VS 2013 & 2015 from my system. I uninstalled every bit I could find that said anything about VS. I then reinstalled it, default installation, everything went fine. Then on start up I get a splash screen that says my 30 day trial evaluation period has ended. I refresh my credentials, then click on the "Check for an updated license" and it says "Failed to download a new license." I know my username and password are fine because I can even Visual Studio profile online and create a team service project, which will even load up in VS 2015 but the splash screen still pops up and blocks me from touching anything else. Has anyone ever come across this and found a solution? I tried looking on past posts and they all say click on the "Check for an updated license" link, It doesn't work for me.

Close Visual Studio
Delete %localappdata%\.IdentityService\SessionTokens.json
Open Visual Studio, "Reenter credentials" and then "Check for an updated license"

Run it as administrator. That worked for me.

I've seen this before, I think that there are a couple places to check:
My problem was solved through this thread:
License expired after installation Microsoft Visual Studio 2015 community
System Date on your machine, sometimes if this is set incorrectly it can mess with the licensing. This wasn't my problem.

What worked for me was to log in to my account. Then, I was able to successfully download and update the license; otherwise it failed to download.

Visual Studio Freezes when I try to Add a file

I have an ASP.NET MVC application that I'm working on in Visual Studio 2013 Premium. I have three projects that are underneath my solution. If I right-click on any of the folders that are immediately under my solution and choose add, the flyout from the context menu displays fine and Visual Studio continues to function normally.
If I right click on any (I've tried a few but not all) folder underneath one particular project in Visual Studio, it freezes for about fifteen minutes. The cpu and memory usage when this is going on seem pretty normal.
If I right click on any of the folders underneath the other two projects and choose Add I get the flyout to appear showing the types of things I can add to the folder and everything works just fine.
What I've tried:
Disabling all Visual Studio Extensions that can be disabled. This didn't fix it.
Starting an instance of Visual Studio in Safe mode, this does fix it.
Any idea what I can try next? I'd hate to have to manually uninstall all of the Visual Studio extensions that can't be disabled, but this seems like the logical next course of action.
As far as Extensions I have:
Application Insights Behaviors SDK (XAML)
Bing Dev. Assistant (Disabled, installed after problem started)
Find in Solution Explorer (Disabled)
Company-created Build Tools (Disabled)
Company-created Core Tools
Company-created Scaffolding Tools (Disabled)
Microsoft Advertising pubCenter
Microsoft Advertising SDK for Win 8.1
Microsoft Advertising SDK for WP 8.1 XAML
Microsoft ASP.NET and Web Tools
Microsoft Visual Studio ASP.NET MVC 5 Scaffolding
Nuget Package Manager
Productivity Power Tools (Disabled)
Release Management for VS 2013
TFS Server Power Tools for VS 2013
TFS Sidekicks (Disabled)
TFS Process Template Editor
TFS Team Collab.
TFS Work Item Type Designer
Unit Test Generator (Disabled)
Visual F#
VS Extensions for Windows Library for JavaScript
WP 8.1 SDK Integration
Workflow Manager Activities
I don't need the WP 8.1 stuff here at work, but dabble with it at home. Since I'm logged into my MSDN account in Visual Studio at both places, would it uninstall it from my home PC if I uninstall it at work?
I'm doing a little further exploration. On the project that has the problem, when I try to do an add to a folder, I'm seeing Nuget.exe get fired off every six seconds over and over again. Where would I look to see where this is set up? I assume in the .csproj file.
Thanks

I disabled and uninstalled a bunch of Visual Studio extensions, which didn't help. I then cleared my nuget cache and that solved my problem.

I had exactly the same problem apparently, in my case it was a reference problem try deleting them one by one until the it starts responding in real time, i suggest starting with 3rd party dlls.

When creating a WCF project in VS2010, I get "Error : WcfProject.csproj cannot be opened. The project type is not supported by this installation"

hey there. So, we have a VS2010 project and the VisualSVN server on one machine. We added a new machine with the client visual svn and the projected loaded in. except for the WCF service. i'm getting a...
" error : the project file c:/..../wcfProject.csproj cannot be opened.
The project type is not supported by this installation."
i've checked the directory, the files and file structure are there and the same as the main development machine. any tips/solutions?
thanks
David K.

I had a similar problem with some WCF solution which I downloaded from a blog.
The solutions of running deveng with the switches did not resolve my issues. After some more searching it turned out that the following clue in the answer of Ralph Willgoss lead to the solution of my problem:
I resolved it by installing the Visual Web Developer.
I also had to (manually) install the Web Platform Installer to (automatically) download the last requirements for the project to properly load.

I had a similar problem when trying to create a new project of the following types:
WCF Service Application
WCF Work Flow Service Application
Syndication Service Library
I was using Windows 7 Ultimate 64bit, with no other versions of Visual Studio installed.
I also had tried many other options, such as:
devenv /resetsettings
devenv /resetskippkgs
ensuring I had C++ option of VS2010 installed
VS2010 Service Pack 1
I resolved it by installing the Visual Web Developer.

There are a few things this could be so I can't give you one specific answer. However, here are a few things to try on your machine that is throwing the error:
First, verify which version of Visual Studio is set as the default for opening csproj files. It could be that you installed SQL or something else that uses an older version of Visual Studio. Sometimes that can give an error. Even if the default is the Visual Studio version selector I've seen it throw an error. Open up the correct version of Visual Studio (through the Programs menu) and then inside Visual Studio try to open the package. If that works, you know the issue is with which version is opening the file.
If that doesn't work, you could try resetting the Visual Studio settings. From the run menu type devenv /setup This should reset the Visual Studio environment and hopefully it will fix the issue. If this does not work, try running devenv /ResetSkipPkgs from the Run menu. This will try to load any packages that Visual Studio previously skipped.
If these steps don't work, let us know. Give us any further error messages that come up after attempting these steps.