cannot access any pdf files
I have a macbook pro, 10.13.6. I purchased adobe acrobat dc about 4 hours ago, and it won't let me open any of my pdf documents. I get this: "There was an error opening this document. Acrobat cannot open this file because a task is still active in Acrobat. Please return to Acrobat and end the task before opening this file." I have forced the application to quit through the Activity Monitor and forced my computer to shut down, but I still can't access any of my pdf files. If I load them onto sharepoint I can see them, but I can't open them through adobe acrobat dc.