Save Changes prompt after closing should allow the program to close.

[pharan]

CURRENT BEHAVIOR
Close Spine while your project is unsaved.
It asks if you want to save your project.
After you choose save, it saves, but then Spine doesn't close.

EXPECTED
Close Spine while your project is unsaved.
It asks if you want to save your project.
Then after your choice— save, or don't save— it should close it.

http://esotericsoftware.com/forum/Prompt-to-Save-Nitpicking-9158

[NathanSweet]

3.6.40