Files containing a filter layer usually crash on save. I've tried about 5 filters and all of them did it.
Create a new file, add a filter layer such as blur, save.
Version: 5.2.0-prealpha (git 31ed09f)
The problem crops up in that specific nightly build, the previous build before it, 477bf9f, does not have the problem.
*** This bug has been marked as a duplicate of bug 459252 ***