I don't know but mine did the same thing. I guess from all the times I had to erase overdrive and put it back.
Adobe Live Chat: http://www.adobe.com/support/chat/ivrchat.html
They can reset your authorizations, and then you must reauthorize any devices you still need.
(Unfortunately, Adobe haven’t got round to an admin website for viewing and editing authorizations.)
Some of the representatives haven't been properly trained and don't know what to do (and claim there is nothing they can do);
in that case the only way seems to be to give up that chat and try another session hoping for a properly trained representative
If your problem is with another device using Overdrive, Bluefire, Aldiko or similar third party app, it is recommended not to mention that app when on the chat, just mention that you have run out of authorizations (E_ACT_TOO_MANY_ACTIVATIONS) . Thanks to AJP_Bear for that tip.
Thanks for responding, but the chat seems to be down, or at least it's not accessible. I'm going to try to call, or wait until Overdrive updates its app. We'll see. Thanks again
Good luck with calling.
I did just get as far as a live chat link that said there was an agent available.
There were a few extra steps to click through now before you get there, starting at the link I gave.
I finally was able to chat this morning, and apparently I got the right agent. He reset everything, and now Overdrive works again! He said you get six activations per account. Four left! I will be more wary of updating in the future, I probably should not have uninstalled/reinstalled Overdrive as they told me, because that's what invalidated the authorization. Anyway, I just wanted to let you know it's working.
Thanks so much for your help.