Table & is not transparent

What causes this issue?

Transparent matchcode IDs (update type I) are implemented directly as a
database view. Therefore they may only contain transparent tables.

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?

Remove all the tables which are not transparent tables from the
matchcode ID.

Error message extract from SAP system. Copyright SAP SE.