&2 &3 locked by user &1; Remaining repeat attempts: &4

CAUSE&
The selected object is locked by another transaction or another user.

System Response

The system cannot process this object at the moment but will
automatically
IF &V4& EQ 1
try again.
ELSEIF &V4& LT 1
make several repeat attempts.
ELSE make a maximum of &V4& repeat attempts.
ENDIF

How to fix this error?

If message E9 029 is displayed later on, take note of the information in
the message. If message E9 029 is not displayed, you do not have to take
any further action.

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.