Botched upgrade - how to recover?

I was upgrading from 0.5 to bring it up to date.
Got to 1.0, and 2.0 ok
Upgrading from 2.0 failed. In trying to recover, I may have invoked the upgrade to 4.x as well

My first symptom is I can't login to the gui:

exception 'OMV\Rpc\Exception' with message 'Failed to connect to socket: No such file or directory' in /usr/share/php/openmediavault/rpc/rpc.inc:140
Stack trace:
#0 /var/www/openmediavault/rpc/session.inc(56): OMV\Rpc\Rpc::call('UserMgmt', 'authUser', Array, Array, 2, true)
#1 [internal function]: OMVRpcServiceSession->login(Array, Array)
#2 /usr/share/php/openmediavault/rpc/serviceabstract.inc(124): call_user_func_array(Array, Array)
#3 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod('login', Array, Array)
#4 /usr/share/php/openmediavault/rpc/proxy/json.inc(95): OMV\Rpc\Rpc::call('Session', 'login', Array, Array, 3)
#5 /var/www/openmediavault/rpc.php(45): OMV\Rpc\Proxy\Json->handle()
#6 {main}

Along the way, I manually added a group "openmediavault-config" since there was a complaint about that missing

Currently, the SMB process must be ok, since I can see my data drives from windows.

The Plex server is not responding.

I am not sure what to do next to try to recover. I appreciate any help!

I am concerned about losing configuration information. For a fresh install, would I be formatting the system disk and starting from scratch?
Is there a way to export the current OMV configuration information from the commanline?

Thanks for the suggestion. I did the re-install and re-config and everything is working fine now.
It is tedious to reconfigure everything.

Now that I am on 3.x, is the best way to record my configuration still to copy the config.xml and take screenshots of the GUI?