ORA-59050
ASM disk expel failed during rebalance of group '%0!s'.
Cause
Some or all ASM disks in the DROPPING or FORCING state were not expelled from the disk group during rebalance.
Action
Rebalance has restarted to address this issue, so no immediate action is needed. See the alert log for more information on the reason for the failure. If rebalance keeps hitting this error, check the status of the configured ASM network interfaces. Add back all the disks in the DROPPING or FORCING state and retry the rebalance operation.