One issue iam often running into is that Thunar have a habbit to crash/freeze when iam located at a folder who is containing many big files.
Also a folder who is having somekind of activity (a file is being copied) (you are compiling any kind of program) etc will also result in a crash/freeze.

Another funny issue is that a folder who have had this kind of activity and if Thunar did crash/freeze on that folder, will continue crash/freeze on the same folder even if it dosent have any kind of activity.

If i move all the files from that folder into a new folder Thunar wont crash/freeze. I dont know if this is a known bug, but i havent seen it here on BugZilla, and it seems to never been fixed either.