UnauthorizedAccessException after installing Visual Studio Tools for Unity

I recently installed the Visual Studio Tools for Unity following these instructions. (Using VS 2013 Community Edition and Unity 5.0.0f4 personal.)

After installing, Unity seems to be successfully generating a VS solution file and opens VS when I double-click a script in the Unity editor, as expected. However, I'm frequently getting this error:

UnauthorizedAccessException: Access to the path "Library\UnityAssemblies\UnityEngine.xml" is denied.

This error doesn't actually seem to prevent anything from working correctly, but it's popping up when Unity compiles my code, when I run my project in the editor, or when I build a standalone version.

Any idea what would be causing this error or how to resolve it?

 

I've seen this before, it usually goes away after restarting Unity. Have you tried that? Otherwise you could try deleting the Library folder, Unity will regenerate it.

 

Restarting Unity did not fix it, but restarting both Unity and Visual Studio seems to have done so.

 

I am having the same issues using the same versions as the original poster.
Restarting the editor and VS may help in the short term, but issue comes back later. Does anyone knows the cause to it and/or permanent solution? Could that be related to antivirus locking the file?

 

Same problem here. I'm investigating why this happens for the last couple of weeks and with no luck.