Acrobat doesn't let me edit my pdf's

Hi there! I have a creative adobe subscription and that includes acrobat. But this morning my arcobat won't let me edit my pdf's anymore. I can only open them or print them directly. This is very frustrating and I don't know how to fix it. I have a older mac version ( 2015) but never had any trouble with it. 2019.010.20099 is the current version i'm working in. I also can't update it or download another one because it says it's incompatible. 

Many thanks in advance for the help!