Okay that resolved the issue. So in the end Job exception: wrong number of arguments (given 0, expected 1) this issue is caused by either or both Private Topics Plugin and Discourse Follow plugins. Maybe both combined creates this issue I don’t know and I don’t think I want to find out. I am a bit traumatized here dealing with this issue for 21 days. 
Maybe authors of this plugin would like to know this so I am going to tag them here: @sam @RGJ
Thank you @JammyDodger @Firepup650
I guess I learned how to debug a Discourse issue and never to install more than 1 plugins at a time…