Error #3438 on CBT Backup: License Restriction?

Griffin Pembroke

Hi all,

I'm getting stuck trying to perform backups using CBT for my VMs. Every attempt fails with error #3438, and the full message is:

Xapi Error: This operation is not allowed under your license. Please contact your support representative (CBT backup failed)

This seems to imply my current license tier doesn’t support CBT functionality. Has anyone encountered this before? If so:

Is there a way to confirm the license limitations?

Any known workarounds (besides upgrading)?

Thanks in advance for any insights!

Sylas Beaumont

Griffin Pembroke

Ah yes, I encountered the same #3438 error not long ago! So frustrating. 😩

From what I understand (and what others have told me), this is most likely because your version does not support this feature.

Iris Li

Thank you for raising this issue. We’ve confirmed the root cause and provide the official resolution below:

The #3438 Xapi error occurs because CBT is exclusively available under XenServer Enterprise Edition or Platinum Edition licenses. Standard/Free licenses lack CBT capabilities, triggering this permission error during backup operations.

TO SOLVE THIS:
Alter Incremental Mode to Speedkit or ordinary when create new VM Backup job in Backup>Backup Strategies>Advanced Strategy>Incremental Mode and backup again.

Griffin Pembroke

Iris Li Solved! Thanks everyone – especially for confirming the license limitation and the workaround. Switched to Speedkit mode and backups are running fine now. Really appreciate the help! 🙏