Not all equipment was converted

What causes this issue?

The system cannot convert all the equipment. The equipment to be
converted may have been locked by another user.

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?

Use this report to analyze by log output which equipment cannot be
converted.
If necessary, restart the report or use the results to analyze why the
conversion cannot take place.

Error message extract from SAP system. Copyright SAP SE.