edjec wrote: Show subscription plans at registration: Yes
Allow Free Registered Users (without subscriptions): No
Create Subscriptions also for free lifetime plans: Yes

The second setting here means that CBSUbs will not allow users to login if they do not have a valid subscription. If you want them to be able to login as registered users, then you need to change this to Yes.

If you have a Free lifetime plan defined in CBSubs and you offer people the choice during registration to choose this plan, then the last setting needs to be set to Yes in order for CBSubs to create such subscription in its database.

The case you mentioned with:
Allow free subscriptions = No
Create subscription for lt plans = No

just gives you a warning that basically means that people need to have a valid paid subscription to use your website.

If someone in this case does not have a valid subscription they will be presented with upgrade proposals (based on the CBSubs plans you have configured).