SOS unchecked some modules related to support ticketing leads to critcal failure ...

unchecked some modules related to support ticketing like support chart etc ( except the mainsupport module) leads to critical failure. I get this error when i login as admin. unable to

Fatal error: Call to undefined function support_client_access_callback() in /home/sacoin/public_html/sunnyvale-chennai.in/sites/all/modules/entity-7.x-1.0-rc1/entity/entity.module on line 427