Adobe Acrobat Pro DC cannot Save As

Were you trying to save it to a location where you need to set the Security & Privacy settings? 

You say you did an update the other day but you didn't say if it was your OS or Acrobat. Occasionally you need to reset Acrobat's access to Security & Privacy after updates. Here are the instructions for Bridge, just insert Acrobat and the process is the same.

Setting security permissions.

This is not the fault of Adobe or anyone; this is Apple making sure that applications that have not been given permission to access areas of your computer cannot access those areas of your computer.

Go to your System Preferences and select Security and Privacy (found in the top section). Now click on the Privacy setting (last tab). Now click on the lock on the bottom left and provide your Administrator code. Now select the Full Disk Access option and click on the "+" symbol. This will bring up the standard Mac Open window and let you add any application you want or need to have full access. Look for Bridge, select it; it will now appear in that window, and make sure it's checked. Next, go to the Files and Folders option and do the same thing as above (although there's nothing to check, just add. Close everything down and see if that makes it all work.

Please let me know

[Note: these images are from an older OS, the process is the same.]

Close everything up and you should be good to go.