SDL Tridion: Unable to expand publications in CME tree view

I had a problem in Tridion yesterday where I couldn't expand any publications in the CME tree view that contained an Audience Manager folder. It just threw up an error something like "Folder with URI tcm:8-2-196672 does not exist".

The way I worked out the problem related to Audience Manager was by doing a Find in Files in the Tridion Program Files folder searching for 196672. This matched a few config files and pointed to the problem being loading the Audience Manager folder. Eventually after a bit of digging around I found out how to disable Audience Manager in the GUI (see last post):

http://stackoverflow.com/questions/10402198/unable-to-open-publications-an-item-with-the-title-segments-already-exists

This got me to the point where content editors could start publishing pages again.

I started digging around the Tridion_cm_email database to try and find the mapping between publications and folders. The FOLDERS_OWNING_PUBLICATIONS table only had one row in it which seemed suspicious. So I restored last night's backup to a tempdb and the same table had many rows.

After restoring the previous day's backup of the email db everything is back to normal. I still don't know for sure what caused the issue. My assumption is that a recent content port included some dependencies that caused the Audience Manager settings to be overwritten. I thought I'd write an article about it since the error message is slightly esoteric and this might save someone a bit of time if they are having a similar issue.