I'm having intermittant errors exporting a capture file as a presentation. Most of the time I get a 'Export Presentation Error' which says 'An internal error occured'

If i select all the fixtures and delete them it then works. then I undo to get them back and try again and it works. Then future exports again will fail. Can anyone help?

Here's the file.

https://www.dropbox.com/s...h%20Theatre.c2p?dl=0