SAP Message V1810 - Plant can no longer be changed

Diagnosis
The plant can no longer be changed in the following situations:
The item has been assigned to a project.
There is a production order for the order item but it is not a staticassembly order.
Costs have already accrued.
By changing the plant, you change the system settings for the itemcategory or requirements class so that their configuration differs tothat in the current controls.