Action not possible; displaying updated data

What causes this issue?

You want to change the hierarchy in collective processing (for example,
insert, delete, or move nodes). However, the hierarchy has been changed
in the meantime (in a different session/window). That is why you were
not able to carry out the action.

System Response

Your change was <ZH>not</> made. The system has, however, loaded the
current status of the hierarchy and is now displaying it, meaning it is
now possible for you to carry out the action.

How to fix this error?

Carry out the action now in the updated hierarchy.

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.