Reading the above, it looks like you restored an older snapshot to the VSX appliance, however the SMS/MDS still believes the version is R81.10 hence you are getting this issue.
I would suggest you need to do one of the following:
- Restore the correct version snapshot (if you have this).
- Rebuild the appliance as R81.10 and ensure all the GAIA level configurations are exactly the same and the run 'vsx_util reconfigure', this will convert the gateway into VSX and push down your VS configurations. If you have any custom configurations, then you need to ensure you put these back on after.
Think of this are a hardware failure and you now need to replace the node.