Upgrade to 6.6.0 causing readynasd service not to start

After upgrading to 6.6.0 from 6.5.1 the unit is stuck in "Booting 89%" and I'm unable to access the web admin interface. I'm still able to access shares and SSH in hence the following logs. Here are the logs fo the readynasd service:

Oct 12 21:23:14 KNS-NAS-01 systemd[1]: readynasd.service: Unit entered failed state.
Oct 12 21:23:14 KNS-NAS-01 systemd[1]: readynasd.service: Failed with result 'exit-code'.
Oct 12 21:23:14 KNS-NAS-01 systemd[1]: readynasd.service: Service hold-off time over, scheduling restart.
Oct 12 21:23:14 KNS-NAS-01 readynasd[19566]: readynasd log started
Oct 12 21:23:14 KNS-NAS-01 readynasd[19566]: readynasd started. (restarted=0)
Oct 12 21:23:14 KNS-NAS-01 readynasd[19566]: DB (main) schema version: 21 ==> 21
Oct 12 21:23:14 KNS-NAS-01 readynasd[19566]: DB (queue) schema version: new ==> 0
Oct 12 21:23:14 KNS-NAS-01 readynasd[19566]: rndb_sql_get_scaler_mprintf is called with SQL which has vector output. (ncol=1, nrow=2).
Oct 12 21:23:14 KNS-NAS-01 readynasd[19566]: SQL Error for SELECT FROM `group`.
Oct 12 21:23:14 KNS-NAS-01 readynasd[19566]: rndb_account_import() ==> 3 (238ms)
Oct 12 21:23:15 KNS-NAS-01 readynasd[19566]: rndb_import() ==> 3 (450ms)
Oct 12 21:23:15 KNS-NAS-01 readynasd[19566]: Error rndb_import() ==> rc=3
Oct 12 21:23:15 KNS-NAS-01 readynasd[19566]: dba import failed
Oct 12 21:23:15 KNS-NAS-01 systemd[1]: readynasd.service: Main process exited, code=exited, status=255/n/a
Oct 12 21:23:15 KNS-NAS-01 systemd[1]: readynasd.service: Unit entered failed state.
Oct 12 21:23:15 KNS-NAS-01 systemd[1]: readynasd.service: Failed with result 'exit-code'.
Oct 12 21:23:15 KNS-NAS-01 systemd[1]: readynasd.service: Service hold-off time over, scheduling restart.
Oct 12 21:23:15 KNS-NAS-01 systemd[1]: readynasd.service: Start request repeated too quickly.
Oct 12 21:23:15 KNS-NAS-01 systemd[1]: readynasd.service: Unit entered failed state.
Oct 12 21:23:15 KNS-NAS-01 systemd[1]: readynasd.service: Failed with result 'start-limit-hit'.

I've tried renaming the database files in /var/readynasd so the service would recreate them, but that doesn't help, still get the same errors. Some other things I tried:

root@KNS-NAS-01:/var/readynasd# sqlite3 /var/readynasd/smart.sq3 'pragma integrity_check;'
ok
root@KNS-NAS-01:/var/readynasd# sqlite3 /var/readynasd/event.sq3 'pragma integrity_check;'
ok
root@KNS-NAS-01:/var/readynasd# sqlite3 /var/readynasd/db.sq3 'pragma integrity_check;'
ok

Any other debug information I should provide to help debug?