Adobe Digital Editions reader suddenly needs authentication

I have been using ADE to read ebooks and then suddenly it won't download books and i can't open the already downloaded ones. I have uninstalled and reinstalled the program 2X but did not work.  It won't accept my authentication ID and PW [they are correct] get the message

and then when I put in my adobe ID I get the following message

I don't know what to do as I download books directly from my university account.

any help would be most appreciated.