snapshot failed quiesce the virtual machine

Hi All,

Vm backup failling with snapshot error (156)An error occurred while saving the snapshot: Failed to quiesce the virtual machine.

below is the error message:

4-03-2016 23:17:20 - Critical bpbrm(pid=13524) from client : FTL - VMware_freeze: VIXAPI freeze (VMware snapshot) failed with -1: Unrecognized error
14-03-2016 23:17:20 - Critical bpbrm(pid=13524) from client : FTL - VMware error received: An error occurred while saving the snapshot: Failed to quiesce the virtual machine.
14-03-2016 23:17:20 - Critical bpbrm(pid=13524) from client : FTL - vfm_freeze: method: VMware_v2, type: FIM, function: VMware_v2_freeze 
14-03-2016 23:17:24 - Critical bpbrm(pid=13524) from client : FTL -        
14-03-2016 23:17:24 - Critical bpbrm(pid=13524) from client : FTL - vfm_freeze: method: VMware_v2, type: FIM, function: VMware_v2_freeze 
14-03-2016 23:17:24 - Critical bpbrm(pid=13524) from client : FTL -        
14-03-2016 23:17:24 - Critical bpbrm(pid=13524) from client : FTL - snapshot processing failed, status 156   
14-03-2016 23:17:24 - Critical bpbrm(pid=13524) from client : FTL - snapshot creation failed, status 156   

Please help on this.