Can you post or email the .spine file?
contact@esotericsoftware.com
Got it, thanks.
I've improved the error message so it tells what attachment has the problem. The problem is with the attachment "Bravo5" (under slot "Bravo5", not to be confused with the "Bravo5" attachment under slot "Bravo7"!), whose mesh vertices show up as a single point in Spine. I've fixed a different problem where clicking Edit Mesh for this attachment would cause Spine to hang.
Digging deeper, Bravo5 is a mesh with a strange problem
it seems to not have any triangles. I've added code to protect against this and issue a warning when a project is loaded. The project can now be exported and imported again. There is no problem with having many slots without attachments.
I'm not sure how this attachment got created with such bad state. I've never seen it happen. If you can manage to reproduce the problem, I'd love to get it fixed.
