What is the CallManager version?What version of MCU are you using?What is the phone load?Are you using SCCP or H.323?

A cisco document says MARS supports only McAfee Foundstone/Foundscan version 3.0, 5.0 and 6.0. And the error message state credentials are not defined properly.http://www.cisco.com/en/US/docs/security/security_management/cs-mars/6.0/compatibility/lo...

What version of the CUCC are you using? What Version and Release of the CM and ICM Software are you using?

Check your access list configuration.

You can use clear mac-address-table dynamic address, and will generate the mac-address table again to confirm that is being learned correctly.