ObiColliderGroup missing

[Wilbert]

Just upgraded my project to ObiRope 3.2.
But in this version ObiColliderGroup is missing.

Now my project is messed up 
- There is no ObiColliderGroup parameter in ObiSolver:
https://drive.google.com/file/d/1RRyZ-Lf...oI7Tg/view
- Pin constraints are gone
- Add Pin Constraint button does not work (clicking does nothing)
- Edit particles gives an error:
NullReferenceException: Object reference not set to an instance of an object
Obi.ObiParticleActorEditor.DrawParticles () (at Assets/_Tools/Obi/Editor/ObiParticleActorEditor.cs:332)
Obi.ObiParticleActorEditor.DrawActorInfo () (at Assets/_Tools/Obi/Editor/ObiParticleActorEditor.cs:598)
Obi.ObiParticleActorEditor.OnSceneGUI () (at Assets/_Tools/Obi/Editor/ObiParticleActorEditor.cs:262)

How do I fix this ?