Error Extracting Public Key from .snk

My project has started regularly exhibiting this error;

Error       Error extracting public key from file 'FishTracker.snk': The process cannot access the file because it is being used by another process. (Exception from HRESULT: 0x80070020)   FishTracker C:\Users\dom\Documents\Visual Studio 2015\Projects\FishTracker\FishTracker\vbc

Has anyone else experienced a similar error and can shed some light on what other process might be using the file? I've looked closely at task manager and can see no indication of anther process that might be using this. Restarting the machine does cure the issue.

If it's possible that the .snk file has become corrupted is there intrinsically anything wrong with deleting it and creating a new one?