CB Condition shows empty tabs!?

There are different user groups with different profile requirements.
I call a CB Subs plan directly with CB conditional step by step enabled.

Now the plugin shows many tabs that are just empty...

Don't combine CB Conditional hide/show with CBSubs hide/show. They will fight for control of visibility. Use one or the other to control visibility of a tab or field. CB Conditional will only disable an empty tab if the fields on that tab were hidden by CB Conditional; it does not know CBSubs exists along side it.

So what is the trick?

Create a field and auto action it when a plan is called and make the tabs dependent on this field value?

For CBSubs to disable a tab it would need to be designed to do just that. It's best to let CB Conditional do show/hide, but it can't currently do this based off CBSubs plan (I'd like to add such a feature, but no idea when). Otherwise try not to setup tabs where they can be entirely empty by a CBSubs plan.

I realy need the tabs for the one plan but not for the other which makes the setup an incomplete solution.

What about ti diable cb conditional registration for a specific plan.

Is that possible?

No, you can disable Step by Step though I guess and just have a normal registration form. It's possible for the empty tab check to check for CBSubs classes, but it won't make much a difference as CBSubs won't fire the CB Conditional jQuery function (which it can't as it's self contained) to hide the tab.