Hello Ayong
After doing some research, I have found that this is a bug that has to do with version 9.1(5)16 as well as 9.1(7)32. I hope that this isn’t a production device that you are using, because others have experienced this issue which appears with the ASA software upgrade, but does not disappear when they downgrade to a working version. Others have had to open TAC cases to resolve it. Unless I’m mistaken, there doesn’t seem to be any published solution to the issue that I could find, beyond approaching TAC.
I hope this has been helpful!
Laz