Hi,
That is an open caveat for the entire 9.1 version of ASA OS.
http://www.cisco.com/c/en/us/td/docs/security/asa/asa91/release/notes/asarn91.html#36275
https://tools.cisco.com/bugsearch/bug/CSCun37690
And also there is no work around or fix planned for this bug...
Regards
Karthik