The new forge is looking great! Can't wait to get to grips with it and get it all setup nicely

One issue I've hit:
In the forge, going to Admin > Edit Project Info and then saving the updated info takes me to a page which just says "Unhandled PropelException". The variables I enter don't seem to matter - even saving the same old info gives this error.
Any advice appreciated.
Cheers,
Ben.
EDIT: This only happens on my project 'vmart_cb', my other project 'anjel-cb' works ok for this action.