Assign a sequence number for characteristic &1

What causes this issue?

Characteristic &V1& is used as an attribute. To establish a sequence
for the display of custom characteristics, you must assign a sequence
number.

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?

Assign a sequence number.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.