Why am I now being asked for my Adobe ID password to open PDF files?

I had a similar problem on my Macbook Pro running 10.13.6. Adobe Acrobat Reader version 18.011.20058.  After trying to open files that are saved locally to my laptop, I kept getting the Adobe login prompt. There was no cancel option and clicking on the red circle, which would normally close the window, accomplished nothing.  I could not quit/close down adobe reader normally: 1) selecting File-->Quit or 2) Command-Q.  The only other option, other than being forced to log into my Adobe account, which is an exceptionally intrusive violation of my privacy, was to force quit the program. 

I solved this problem by deleting Adobe Acrobat Reader.  When I next tried to open a PDF saved on my machine, it opened perfectly in Preview.  No unnecessary login to my Adobe Account required.  Productivity has now resumed and I can now complete the tasks I set out to accomplish before running into this problem.