Adobe Acrobat wants to use your confidential information stored in “Adobe.APS"

[DavidHoffmanuk]

While working with Adobe Acrobat Pro DC I repeatedly get the dialog “Adobe Acrobat wants to use your confidential information stored in “Adobe.APS” in your keychain”. This keeps appearing but does not recognise my password. I am unable to dismiss the dialog or continue but have to force quit, losing recent work. 

Searching online I can see many other users having similar problems over the last decade but no solutions. Does anyone have an answer?

Thanks

David