content locked message on Kobo

Help!

This is very odd..

I borrowed a book from the library, opened it in Adobe Digital Editions, and transferred it to my Kobo as usual.

I have been happily reading the book for a week now on the Kobo, and then overnight, when I next went to read the book, I am getting an error message:

"The content you are trying to view is locked.  Please use your Adobe ID to authorize your ereader with the Kobo Desktop application or Adobe Digital Editions"

The book is still on my computer in the Adobe Digital Editions, and I can read it there.  It doesn't expire for another 9 days.

I have tried to reload it to the Kobo - didn't work.

I have logged in and out again of both ADE and Kobo - didn't work.

And can't see anything in either on "authorizing the ereader".

ANYONE HAVE ANY IDEAS ON WHAT I SHOULD DO???????

Thanks.