Invalid partner number: &

What causes this issue?

The check routine for partner number &v1& (partner type &v2&) could not
be called. The master data for the partner is missing.

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?

Check whether the master data for partner &v1& has been deleted.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.