This is a problem with the menu group admin feature.
How to reproduce:
- browse to admin/menugroup
- tick 'delete' in a menu group (I chose the first, which was 'visitors')
Although subsequent pages load, they break at the point where menus would be rendered with a message like this:
ERROR(8) "/home/openfontlibrary/cchost.5_0_0/cchost_lib/cc-template.php(857) : eval()'d code"(86): Undefined index: group_name [2008-10-27 05:30 am][my-ip-number-here][/admin/menugroup]
Down for upgrade, check back soon
Troubleshooting new installations
Resetting menus (admin/menu/revert) cures the problem but does not allow me to delete the menu group ;-)
I don't know if this would happen with a vanilla installation. I changed skins and the problem persisted.