No value was assigned to "&"

What causes this issue?

You have not assigned a value to characteristic &V1&. However, you must
assign a value to characteristic &V1& in this situation.

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 value to characteristic &V1&. If you do not know what value to
assign to this characteristic, you can use the function "Change status"
to set the characteristic value assignment status to "incomplete".

Error message extract from SAP system. Copyright SAP SE.