Deleted address used in contract account &1 for alternative payer &4

What causes this issue?

The address (name: &V3&) has been deleted in the business partner.
However, it is still used as selected partner address for the
alternative payer &V4& in contract account &V1& with partner &V2&.

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?

Using the pushbutton <LS>account</>, go to the maintenance of contract
account &V1&. From here, select another address for alternative payer
&V4&, and apply the changes. We recommend that you select the standard
address of the alternative payer in the contract account instead of a
specific address. The advantage of this is that whenever you make a
change to the business partner address, the standard address is also
used in the contract account.
These changes are then saved when you save the current business
partner.

Error message extract from SAP system. Copyright SAP SE.