Can't access CF Admin after applying hotfix APSB13-13??

Yesterday, I applied recommended hotfix APSB13-13.  Today, I can't get into my CF Admin panel.  I'm receiving a HTTP Error 500.0.

I'm assuming this is an IIS issue related to a new DenyUrlSequence, but I can't find the solution anywhere.  I've confirmed that, in my web.config file at the web root, I have an entry removing the DenyUrlSequence, which SHOULD allow the local machine to access the CFIDE/administrator folder.

1) Can anyone help me pinpoint the problem OR

2) Can anyone tell me how to roll back the hotfix, so I can start over?

Thanks in advance for any help/guidance.