Bitlocker intermediate driver error on IoCallDriver

Hi

I am developing intermediate driver to monitor bit locker device IRPs, to access them I wrote driver that calls IoAttachDevice at driver entry routine to attach bit locker device.
So i receive IRPs in Device-Control dispatch routine but as I try to route them to bit locker device, IoCallDriver(bit_locker_device, irp) returns error 0xc000001.

Would you help me?

best