I've only just realised that my previous game, which was very large, will no longer load into C2. When I load it up, it gets about 75% of the way through the loading bar then gives the error 'Failed to open project .. (name and location)' 'Object name in object parameter cannot be found in project Line 4513 column 49 in space.xml' 'The file may be invalid. Try checking the file in a text editor (projects are saved in XML format)'.
I'm not sure what's causing this or what I'm looking for, or how to fix it. If I open it up in Notepad++, line 4513 just has '</family>'.