Hi
Check no other job is running while you execute this. If there is a locking situation it might result into this. Also check KBA 1821199 for lock entries and table status.
1821199 - Background job takes long time due to liveCache lock log
You need to monitor this situation if it is not consistent but random. If already answered your question follow How to close a discussion and why else raise the concern.
Regards
Rahul