Command file for & locked by another process

What causes this issue?

An operating system file (the cofile for transport request &V1&) could
not be accessed from the program that is running, since it is locked by
another transaction.
The name of the lock file is "&V2&".

System Response

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

How to fix this error?

Execute the function again after a few seconds.
If the message occurs regularly, contact your SAP administrator.

Error message extract from SAP system. Copyright SAP SE.