There are scenarios where some orders may get stuck in the "start-handling" status in the Marketplace and when interacting with the order we receive error information.

Simulation

It is not possible, at the moment, to simulate this scenario.

Workaround

There is a workaround option, however, the order reservation cannot be in status 4 or status 5. If the reservation is not in these statuses, you will need to open a ticket with PS Order Management to attempt to manually unlock it.