Not possible to determine external category for internal item cat. &

What causes this issue?

No external item category has been maintained for item category &V1&
in Customizing.
For example: the internal item category <ZH>3</> corresponds to the
external item category <ZH>L</> for subcontracting.

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?

Maintain the external item category and a short text (if necessary) in
Customizing for Purchasing.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.