Revit 2018 stops working

[mairh_tsek]

Hello all, 

I use Revit 2018.2. Each time that I close a project in Revit I get the below error message (see image), and the program stops working.

Do you know what happened?

Thank you in advance!

[barthbradley]

Is it just one file? Got any Warnings in the Project? 

[mairh_tsek]

Sometimes I have more than one project open, some other just one.

Even if I open a simple project..I get the same message. 

[mairh_tsek]

Hello all,

Any idea what I need to check concerning the problem above? 

I have the same problem if I just open a new .rvt file and close it.