Cant access web gui ubuntu18

I am trying to install Duplicati on a ubuntu 18 VM. I have it working fine on other ubuntu 18 VM’s but this particular one isnt working.

sudo duplicati-server --webservice-interface=
A serious error occurred in Duplicati: System.Exception: Failed to create, open or upgrade the database.
Error message:
The database has version 6 but the largest supported version is 4.

This is likely caused by upgrading to a newer version and then downgrading.
If this is the case, there is likely a backup file of the previous database version in the folder /root/.config/Duplicati.

thats the error im getting.

Is this a new install? You’ve never configured Duplicati before on this VM?