The CBT (Changed Block Tracking) driver in BDRShield may become unresponsive due to environmental problems or handle/memory leaks. Additionally, high levels of I/O can lead to extended snapshot quiescing, potentially causing issues in releasing the CBT bitmap file handle.

To resolve the CBT_FAILURE issue in BDRShield, follow these steps:

1. Restart the BDRShield Integration service (BIS) running on the Physical Hyper-V Host and reschedule the backup.

2. If using SMB storage, restart the BDRShield Integration service (BIS) on the SMB File Server Host and reschedule the backup.

3. Verify that the BDRShield Integration Service running on both the SMB server and Application Server are using the same domain credentials to start the service.

4. If the problem persists, a CBT reset may be required. This process requires technical expertise, so it is advisable to contact our support team for further assistance.