Restart BW Accelerator index server

What causes this issue?

How to fix this error?

The index servers for BW Accelerator are being restarted. This involves
reassigning the indexes. While this action is running, you cannot
search, index, or run any other BW Accelerator actions.
You can start this action from the BW system.

System Response

This action only restarts the BWA index server. Corresponding messages
for the action are displayed in the detailed BW Accelerator Monitor in
the BWA Action Messages area. An application log is also written.
(Object : 'RSDDTZA', Subobject: 'ACTIONS')

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.