Download and install Critical Patch B3291 to enable WFBS 9.0 to support Mac OS X El Capitan.
Critical Patch B3291 is applicable to all localized languages (language independent) of WFBS 9.0 (Standard and Advanced). It is now available in the Download Center.
Trend Micro recommends that you apply Critical Patch B3291 if you plan to upgrade to OS X 10.11 El Capitan. The critical patch can be installed on WFBS 9.0, WFBS 9.0 SP1 and WFBS 9.0 SP2.