Looks like the /etc/ovirt-provider-ovn/conf.d/10-setup-ovirt-provider-ovn.conf does not fit to engine's expectations.

This can be fixed like described in

https://lists.ovirt.org/archives/list/users@ovirt.org/message/POZM22KMV7MT7HNI7M5B6TSLE4PQXRQH/ :

> > How did you update the secret?
> > The procedure would be
> > 1. Run /usr/share/ovirt-engine/bin/ovirt-register-sso-client-tool.sh
> >    with
> >    Client Id: ovirt-provider-ovn
> >    Client CA Certificate File Location: /etc/pki/ovirt-engine/certs/engine.cer
> >    Callback Prefix URL: https://<ENGINE_FQDN>:443/ovirt-engine/
> > 2. Use the SSO_CLIENT_SECRET from the outfile produced by the previous
> >    command in
> >    /etc/ovirt-provider-ovn/conf.d/10-setup-ovirt-provider-ovn.conf
> > 3. Restart ovirt-engine and ovirt-provider-ovn
> >    systemctl restart ovirt-engine
> >    systemctl restart ovirt-provider-ovn
> >
> >
> > If this does not solve the problem and you want to use the
> > ovirt-provider-ovn, please increase logging in ovirt-provider-ovn via
> > sudo sed -i.$(date +%F-%H-%M) 's/INFO/DEBUG/gi'
> > /etc/ovirt-provider-ovn/logger.conf
> > systemctl restart ovirt-provider-ovn
> >
> > and share the ovirt-provider-ovn.log with the error after the restart.
>
> Else you can try to remove or rename the ovirt-provider-ovn provider in
> oVirt Engine, if it already exists, and run engine-setup again like this
> engine-setup --reconfigure-optional-components
> or with answer-file that has 'OVESETUP_OVN/ovirtProviderOvn' enabled:
> 'OVESETUP_OVN/ovirtProviderOvn=bool:True