HI Niyaz
The issue you mentioned was a known issue & has been fixed in SEP 12.1 RU1 MP1
Export of client package from SEPM never finishes
Fix ID: 2627397
Symptom: Export of a client package from SEPM does not complete on non-English Windows, when SEPM is configured to use the embedded database.
Solution: SEPM was modified to use a different database method to obtain binary stream data.
If not using RU1 MP1 then please upgrade the SEPM to latest SEPM version 12.1 RU2
.