When I am renaming files one at a time Thunar closes, it doesn't give an error message, it just closes all open instances of Thunar. Then I can open the GUI windows again to rename a few more files before it blinks out again!
When I do a bulk rename by selecting a bunch of files and pressing F2 key it does not crash?
It's probably the same as : Q: Thunar crashes when copying file and : Q: Thunar 1.6.6 Crashing When Moving .docx File
Found and sent the crash report here: /var/crash/_usr_bin_thunar.1000.crash