I have Overdrive app on ipad. I have working adobe ID on PC. I have Internet connection to ipad. When I try to authorize adobe ID on ipad through Overdrive, it gives me error 256; error connection to adobe servers. I tried several other ereaders. Same thing. Tried on my android phone. Same thing (though a different error number, but wouldn't connect to adobe server). Through forum, tried the date/time settings suggestions. Didn't work. Suggestions?
I assume you have tried a few times a little apart? It could be that the servers were genuinely down for a bit.
I don't know if this happens on Overdrive, but ADE on PC sometimes gets itself half authorized and confused. In that case, you need specifically the deauthorize (ctrl-shift-D on the computer) before the authorization will work.
It looks as if you won't get a deauthorize option on the iPad Overdrive unless it is correctly authorized. You could try uninstalling Overdrive completely and reinstalling it, that could help.