Sometimes ADE gets registration confused.
This can often (not always) be fixed by completely de-registering using ctrl-shift-D to ADE (cmd-shift-D on Mac).
Then restart ADE.
Then tray again to authorize.
Also, there are lots of bugs in ADE 2.0.
Problems can sometimes be resolved using the older but more reliable ADE1.7.2.
Version 1.7.2, it is a little difficult to find, available on Adobe site for Windows and for Mac.
The forum software is sometimes corrupting the link above. There shouldn't be a blank in 'editio ns.html'. The following redirects to the same page: http://tinyurl.com/diged172