Ensure that within CBSubs > Settings > Global you've set free lifetime plans to create subscriptions. Without it the free lifetime plans are basically dummy plans and don't actually store a subscription.

I see, looks like a validation done with the after registration trigger in CBSubs. You're going to have to allow free registrations as CBSubs validation will always fail (single sign on bypasses traditional registration, that's the point of it). My guess is this is due to having Exclusive (required) plans on registration. I've let Beat know that this causes issues for CB Connect to see if something can be worked out for a future release.

I don't know what setup you previously had so I can't tell you what will or will not work, sorry. I do not have access to CBSubs source so I can't tell you exactly what causes that validation error to kick. I would assume you need plans that allow upgrade and are public as well as published. That error is happening directly after the user is registered and before they can login so it has something to do with registration validation of plans selected. I've let Beat know of the error and we will discuss internally what can be done regarding it or if there's some sort of configuration to circumvent it.