Lock Order when spec. Partner Function is maintained

Hi,

my requirement:

When a specific partner function in maintained in opportunity only a defined business role should be able to change the order.

I tried in BT111H_OPPT/OpportunityOVViewSet  method DO_VIEW_INIT_ON_ACTIVATION to lock the context BtadminH with entity->lock and the set an lock with FM ENQUEUE_ECRM_ORDERADM_H before user can change to edit mode.

But in both cases edit is possible.

Then i tried Auth Badi IF_EX_CRM_ORDER_AUTH_CHECK~CRM_ORDER_ADD_AUTH_CHECK.

But when i raise "raise no_authority" WebUI crashed with a BSP Error:

Anyone has a tip?

Regards

Th