For those on Mac OS with authorisation issues, if none of Adobe's advice works

Try opening the Keychain Access utility, and locking the keychain (click the lock icon on the top-left of the utility).

Adobe should add this to their advice on fixing issues on Mac OS, IMHO.

My experience below, —

I've used ADE successfully once (if a little confused by what it was trying to do), but now it has decided to bork itself. I’m on Mac OS, latest version.

Firstly, I dragged an .ACSM file to ADE. It asks for my password. I give it my password, the CORRECT password (I know it is correct), and it claims it is not correct. Well, that’s wrong. Anyway, it issues:

   E_ACT_NOT_READY

So… I read Adobe’s advice, and they say to delete the activation.dat file and start over. I do. (See Error messages and troubleshooting tips for activation errors in Adobe Digital Editions))

Trying again, this time I get:

   E_AUTH_BAD_DEVICE_KEY

So… I read Adobe’s advice, and they say to check the keychain. I do - and the keychain is fine already! (See Error "E_AUTH_BAD_DEVICE_KEY" | Digital Editions | Mac OS X))

Trying to activate without an ID doesn't work either.

So what gives? I can't see any further help on the Abobe site, but there is this tip: E_AUTH_BAD_DEVICE_KEY - please help!  The post is marked as not answered, but scroll down for the answer: basically what I wrote at the top, but with a nice screen cap.