Error with UI.dll

Unity Engine
1

I am in Unity 5.1.4

I am getting this error in the console:

Asset ‘C:/Unity/Editor/Data/UnityExtensions/Unity/GUISystem/Editor/UnityEditor.UI.dll’ is in timestamps but is not known in guidmapper…

The UI objects like canvas, etc are not working in my scene ( the associated script can not be loaded).
I have tried reinstalling Unity but it doesn’t fix the problem.

Any idea?

2

Anybody knows what does this error mean?

3

Usually a windows security thing…turn off real time scanning in any AV application, run unity as an administrator.

I was getting this all the time, everyday. untill I did those things.

P

4

I have tried but it doesn’t work. The error persists.

5

I have solved it.
I deleted the Library folder in my project and when restarting, it rebuild all and fix the error.