visual studio right click missing find all refences and go to definition disabled

Question

I am using Visual Studio 2010, suddenly from right click menu Go to Defination option is disabled and even F12 does not work. Find all referneces option is missing from the menu... i use them a lot, how can I get them work

Answer 1

I had the same problem with Microsoft Visual Studio 2013 Premium.

Fixed it by following the steps:

1. Close your solution.
2. Delete hidden .suo file in folder where your solution's .sln file exists.
3. Open your solution.
4. Rebuild your solution.

F12 should now work.

Answer 2

To reiterate what @eodabash said on 2014-04-07 was EXACTLY it.

I'm using Visual Studio 2013 Premium and I too lost Go To Definition functionality when the file was file containing the class was not opened.

Resolution:

1. Tools > Options > Text Editor > File Extension
2. Notice extension, "cs" was missing from list.
3. Type, "cs" in the Extension box
4. Select, "Microsoft Visual C#" under Editor
5. Click, Add. Click, Ok.

BOOM!

My issue was NOT an extension. It was NOT the .suo files. It was NOT a reinstall issue. It worked in C++ but NOT C#.

It WAS the file extensions option were not associated with C#. (facepalm)