If CAST with type is on & (&, type &), type and length must be the same

What causes this issue?

If you have a CAST on data elements, the type and length of the source
and target must be the same.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.