From Downstream: 

https://bugzilla.redhat.com/show_bug.cgi?id=675594

From the backtrace: 

Program terminated with signal 11, Segmentation fault.
#0  thunar_vfs_job_source_dispatch (source=0x83d9208, callback=0, user_data=0x0) at thunar-vfs-job.c:501
501	thunar-vfs-job.c: No such file or directory.
	in thunar-vfs-job.c

Seems to happen sometimes with video files (doesn't matter which video file). 
Could be a race condition?