Profile parameter FN_AUDIT contains an invalid pattern

In our ECC PDR system we are getting the below warning messages :

"Profile parameter FN_AUDIT contains an invalid pattern audit_++++++++_######, error = 1"

We checked but couldn't find the invalid parameter.

Below are out parameter setting. Could you please help.

FN_AUDIT = audit_++++++++_######

rsau/enable = 1

rsau/max_diskspace/per_file = 52428800

rsau/max_diskspace/per_day = 0

What we can do to remove this warning messages.

Thanks in advance.

Regards,

Ramesh