Visual studio doesn't support specific csproj file
I am getting this error when I try to open the solution file of my project. The solution is 2012 file (checked using notepad).
If I click on Ok, The solution opens up except for one csproject which does not load. I get a migration report in UpgradeLog.htm file, with the following error for the project which failed to load. Could not figure out much from it.
Error:
The application which this project type is based on was not found. Please try this link for further information: http://go.microsoft.com/fwlink/?prd=12395&pver=11&sbp=ProjectTypeDeprecated&plcid=0x409&clcid=0x409&ar=MSDN&sar=ProjectCompatibility&o1=82b43b9b-a64c-4715-b499-d71e9ca2bd60
Does the upgrade report mean that it is a project from previous version of Visual studio? It does not open in Visual Studio 2010 either.
Answer
The error doesn't say that Visual Studio doesn't support .csproj files at all, it says it doesn't support a specific project type in that particular project file. This means this either isn't your project as you claim, or you are trying to build it on a different machine from the one used to create the project.
Visual Studio uses various elements in a .csproj file to determine its project type. See How do you tell the Visual Studio project type from an existing Visual Studio project and What is the significance of ProjectTypeGuids tag in the visual studio project file. It does this so it knows how to compile your project, what properties tabs to show, what context menu options should be available and so on.
Certain project types can cause this error. Usually they require some kind of SDK to be installed on the machine used to open or build the project.
You should search the web for the GUID mentioned in the error message you show (the value after o1=). You can also open the project file in a text editor and find the <ProjectTypeGuids> elements, which contains comma-separated project type GUIDs.
Then search the web for those GUIDs to find out which SDK or tool you need to install in order to be able to open or build the project.
If you paste the specific GUID from your error message in your favorite web search engine, you'll find Problem solved: Visual Studio / There is a missing project subtype. Subtype: '{82b43b9b-a64c-4715-b499-d71e9ca2bd60}' is unsupported by this installation., where it is mentioned you'll need to install the Visual Studio 2013 SDK. This means that in this case, your project is a Visual Studio 2013 extension.
This is what documentation is for. You should at least put a ReadMe.txt file in your project directory, explaining what the prerequisites for building a project are, especially when it won't open or build with Visual Studio out of the box.