I face similar issue described in this post:
I am using VS2010. I have one project not recognize in solution (Unloaded and grey out), when edit the .sln file notices there are unmatched entries:
SccProjectUniqueName102 = CorrectPath\\Modules\\MyProject.csproj
SccProjectName102 = WrongPath/MyProject
SccLocalPath102 = WrongPath\\MyProject
Most of the answers on the internet tell you to delete the .suo file so you will get rid of it, I have tried but no luck, end up I decides to correct the paths manually in .sln file, like this:
SccProjectUniqueName102 = CorrectPath\\Modules\\MyPorject.csproj
SccProjectName102 = CorrectPath/Modules/MyProject
SccLocalPath102 = CorrectPath\\Modules\\MyProject
Save the changes and open the solution again, Visual Studio still prompt me a warning said the ‘MyProject’ failed to load.
Ok, it seems I should try the most popular solution, delete .suo …
Open solution again, and ….. No error/warning message given!
Pheeew, solved it at last.
You will lose your Visual Studio user settings by deleting the .suo file, like breakpoints, opened tabs, expanded/collapsed tree nodes, etc.
Keywords: .suo, .sln, Visual Studio 2010 Solution, Setting