Error when selecting frame

[gaite]

Error when selecting frame (in any way) or opening file: http://pastebin.com/fushN6Pe
Error when using arrow keys: http://pastebin.com/6Yu8VDAA

Clicking on a frame highlights it but doesn't actually select it.
The Previous Frame/Next Frame buttons seem to work correctly, although the error still appears.

If the file is saved and reopened, all cels are missing (not sure if related).

Edit: cels only disappear if they're blank, which is probably intentional. Sorry about that.