E_ADEPT_USER_AUTH error adding Kobo ebook to Adobe Digital Editions

I am trying to add a Kobo ebook to my Digital Editions. I get the E_ADEPT_USER_AUTH error. Have followed the instructions on knowledge base, plus reset my password and uninstalled and re-installed Digital Editions.

No Luck.

Judging from recent error reports this is a system problem that many are encountering.

When can we expect a fix, or is there a known workaround?

DE version: 3.0.86137

Running on Windows 8.1

Further investigation suggests that the fault is in the key from Kobo, since I just downloaded an old key and it worked.