The FusionStorage Block alarms: "VBS failed to load metadata". Which of the following are the possible causes? (Multiple Choice)

The FusionStorage Block alarms: "VBS failed to load metadata". Which of the following are the possible causes? (Multiple Choice)
A . The OSD process is abnormal.
B . The MDC process is abnormal.
C . The communication between the main VBS process and the OSD process is abnormal.
D . Main VBS internal error

Answer: ACD