problem closing Acrobat Reader DC

[reinold de vuyst]

I encounter trouble with Adobe Acrobat Reader DC to close a file. 

I can't close the program by the little cross (upper right corner).

When I close via the task bar, it closes my outlook program as well.

I tried to check the version of Adobe Acrobat Reader DC, but I have no menu bar to click on the help function. Anyone who can help me out?