A customer or Provider on customer's behalf cannot cancel a subscription in PBA Control Panel due to the error message saying that conflicting order exists:
Can not cancel Subscription #1000101: There is already a Cancellation Order #CL000101 in status New(NW). This order prohibits placing an order of All Order Types (Per Subscription). Please either cancel conflicting order or wait while it will be processed or contact Provider.
PBA has built-in mechanism which prevents provisioning of conflicting orders, e.g. PBA does not allow to provision upgrade/downgrade order if another non-completed upgrade/downgrade order exists because it is not always clear what amount of resource must be set for a subscription by two non-completed orders.
Also, PBA does not allow to renew or cancel subscription if it already has non-completed renewal or cancellation order respectively.
PBA provides order number of the conflicting cancellation order. A customer or Provider may find the order in PBA Control Panel and either cancel it or complete the order provisioning. After the conflict is resolved the customer or Provider can place new cancellation order for the subscription.