Plants exist in which you have not specified a control key

What causes this issue?

The QM procurement indicator is selected for the material. If this
indicator is selected, you must also define at plant level a control
key for QM in procurement. However, there are still plants in which you
have not defined this key.

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 material in all of the plants, specifying a control key
for QM in procurement in each case. We recommend you use the
transaction <DS:TRAN.QI05>Mass Maintenance of QM Procurement Keys in
the Material Master</>.

Error message extract from SAP system. Copyright SAP SE.