Location &1, product &2: Fixed orders exist

What causes this issue?

Location &V1&, product &V2&, bucket &V3&: There are fixed orders that
generate demands.

System Response

If there are insufficient capacities to fulfill the demands, the
optimizer might not be able to find a feasible solution.

How to fix this error?

If the optimizer does find a solution, no further action is required. If
not, remove the fixing from the triggering orders.

Error message extract from SAP system. Copyright SAP SE.