The full error can be found here:

https://pastebin.com/5Ue4WJnr

In general I haven't been able to get the latest dev builds working, tried multiple ones and also the newest one from jenkins.

Did you modify the default config? The default config doesn't set default-backend so it appears you have to uncomment and set that yourself.

I'll try and let the plugin generate a new one quickly. I'll inform if it works.

Oh indeed it started up when deleting the config! Thanks.