Could not create form &1 or interface &1

What causes this issue?

You tried to create a form and/or interface. However, these objects are
already locked in a transport request, or you do not have authorization
for the operation.

System Response

The process was terminated.

How to fix this error?

Check whether the form or interface is locked in a transport request and
remove the lock by releasing or changing the transport request.
You can use transaction SU53 to see whether you have authorization. If
you do not have authorization, contact your system administrator.

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.