The contract &1 is not assigned to container &3 on &2.

What causes this issue?

The contract assignment of container and service frequency time slice is
inconsistent. The contract of the &V1& service frequency &V4& is not
assigned to the container &V3& on &V2&.
Please check, if the assignment in the service frequency time slice is
outdated.

System Response

The waste disposal order will not be created because this would result
in invoicing a waste disposal order not having a contract assigned to a
container.

How to fix this error?

Check the contract assignment of the container and the service frequency
time slice. Either delete the invalid contract from the service
frequency time slice or assign the contract to the container.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.