When you see in SCVMM Virtual Machine status "missing", it means scvmm sql db is corrupted, most probably due to cluster mis-operation.
Try to start migrate VM on another host. When you see the duplicate VM and one of them running correctly, then you may remove mising VMs:
The state "missing" has a code 220, and "update failed" 107. You may need to modify script, since the code is hardcoded there:
dbo.tbl_WLC_VObject WHERE [ObjectState] = 220
dbo.tbl_WLC_VObject WHERE [ObjectState] = 107