Material number longer than &1 characters. EDI with limits only

What causes this issue?

You have entered no more than &v1& characters for the length of the
material number. Consequently EDI (Electronic Data Interchange) is no
longer possible with other SAP systems.

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.