Page tree

Versions Compared


  • This line was added.
  • This line was removed.
  • Formatting was changed.

Product Version: 8.5
Last Modified: 04 April 2019


An error message is stating states that the source host did not provide valid CBT/RCT/CRT data for a VM and that the proprietary change tracking technology will be used.


After the initial (full) VM backup or replication, all consequent subsequent job runs are forever incremental. By default, NAKIVO Backup & Replication uses VMware CBT, Hyper-V RCT, and Nutanix CRT technologies to identify what data has changed since the last job run. Factors like power outage outages and other, others can cause these technologies to reset and lose a track of incremental changes for a VM.

The above error message appears in case when the CBT/RCT/CRT error handling is set to switch to the proprietary change tracking technology.


If the problem persists, try editing the job and setting a different error handling on the Options step of back backup and replications replication jobs.