I believe this is the case, at least. The problem is with an extension called VehicleFits, (it's also on GitHub).
EDIT: Here's a bit more configuration info. Magento EE 1.13, VAF 1.34.
Originally, the issue was that a _setActiveMenu() call was causing an error with the text:
Fatal error: Call to a member function setActive() on a non-object in /path/to/my/magento/site/app/code/core/Mage/Adminhtml/Controller/Action.php on line 104 Looking at the blocks available at the time of the _setActiveMenu() call, I see that it's all frontend stuff (cart_sidebar, top.search, etc), and the menu block is not available.
Any clues as to where I should look to see why the frontend layout is being loaded, and how I can ensure that the adminhtml layout is loaded instead?
Thanks!
Some more information...
Here's the definition of the menu from the plugin:
<adminhtml> <menu> <vaf translate="title" module="adminhtml"> <title>Vehicles</title> <sort_order>25</sort_order> <children> <vehicleslist translate="title"> <title>Vehicle List</title> <sort_order>10</sort_order> <children> <local translate="title"> <title>Manage</title> <action>adminhtml/definitions</action> </local> </children> </vehicleslist> <schema translate="title"> <title>Schema</title> <sort_order>200</sort_order> <children> <local translate="title"> <title>Manage</title> <action>adminhtml/schema</action> </local> </children> </schema> </children> </vaf> </menu> <acl> <resources> <admin> <children> <vaf translate="title"> <title>Vehicle Fits</title> <sort_order>0</sort_order> <children> <vehicleslist translate="title"> <title>Vehicle List</title> <sort_order>10</sort_order> <children> <local translate="title"> <title>Manage</title> <action>adminhtml/definitions</action> </local> </children> </vehicleslist> <schema translate="title"> <title>Schema</title> <sort_order>200</sort_order> <children> <local translate="title"> <title>Manage</title> <action>adminhtml/schema</action> </local> </children> </schema> </children> </vaf> </children> </admin> </resources> </acl> </adminhtml> 