Adobe Acrobat Pro DC blank Share, Sign, Fill & Sign Request Signatures window

When I click on Adobe Sign, I get a bar at the top that says Add signers-----Specify where to fill and sign-----Send and track progress, and has a big blank window bleow. Same results when I click on Adobe Sign.

When I click on Share button, there's a blank white square popover. 

Nothing appears after 5 minutes.

I've logged out, uninstalled, removed ~/Library/Caches/Acrobat, ~/Library/Application Support/Acrobat, ~/Library/Saved Application State/Acrobat, ~/Library/Preferenvces/Acrobat,

and the issue persists.

I have had this issue with PDF's I created from Mac OS print to PDF option, from PDF's from other people, and PDF's created in Illustrator.

This issue has been prevalent for a long time now and don't understand why.