Activate unassign rule for plant &1

What causes this issue?

Customization is not maintained for un-assigning stock for this plant.

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?

Go to SPRO->Cross application components->Advanced available to
Promise-> Supply assignment->Cross Applications->assign goods receipt
rules to plants. (For Goods Receipt)
Go to SPRO->Cross application components->Advanced available to
Promise-> Supply assignment->Cross Applications->assign goods issue
rules to plants. (For Goods Issue)

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.