Acrobat crashes few seconds after launch - no tools if I open a pdf

Hello,

I've gone through several topics about Acrobat crashing, but I really can't understand them. 

If I launch the app via Creative Cloud or clicking the Acrobat icon from desktop this is what I see for 3 secs (then it goes away) 

If I open a pdf this is what I see (after a longer wait then usual)

So just the pdf, no tools on right side nor on the top of the window. 
Sometimes I can navigate the pdf.

Other times it just can't open the pdf, so I have a black page. 

If I select "home" I can't see other documents (black page)

If I select "tools" I can't even see the icons and the names of the tools.

What I did already:

Uninstall Acrobat
Clicking very fast on "help" when I launch the app and then "updates" (it dowloaded an update, I rebooted the PC, then nothing, the same crashing)

Repair the app from Windows toolbar list of the apps

I really need the help of an expert,

many thanks,

Davide