I've been attempting ot backup a course to be able to restore at a later date without user data. I first just tried it as an IMC Cartridge. I get the "Must install fileinfo extension". Well, not sure how to do that. So I then I unchecked the IMS Cartridge, and just checked the activities and blocks. It then immediately fails with the "cannot_finish_ui_if_not_setting_ui" error.
I'm running 2.4 on a Windows server. The only "UI" think I can posisble think of is that I've installed Collapsed Topics recently, but another backup went off without a hitch after using it. So I don't know. Any ideas?