Can't Edit a PDF.

Do you have a paid Creative Cloud plan?

Please log-in to your account below to confirm your plan is active and payment details are current.
https://account.adobe.com/plans

1. Open CC Desktop App.
2. Click the gear icon > General tab > Settings. Select "Always keep Creative Cloud up to date."
3. Click on your Avatar (top right image).
4. Sign-out of Creative Cloud.
5. Close all apps.
6. Restart your computer.
7. Open CC Desktop app.
8. Click your Avatar.
9. Sign-in with your paid ID and password.
10. Scroll down to Acrobat.  See screenshot.

Post back if you still need help.

You must stop using Acrobat Reader. Download and install the app you paid for. Acrobat Reader does not change, but the design has left many facing this puzzle. 

Please post the name of the Adobe program you use so a Moderator may move this message to that forum