baconator900 made a lot of research, and discovered exactly what parts are triggering the 'damned jump from the Krakens' on launch:

• hydrogen tank
• converter

As I mentioned in the TODO list, my current guess is something wrong with the collision meshes.

After 3.5 years, I'm finally tackling this down. :)

Damn. I'm getting this error while trying to export the mu file from blender. :(

I think I found the problem!!!!

When you import a DAE file, what you have on the bpy.contect.active_object while exporting to mu is not a bpy_types.Object derived from a MuObject.

So the object hierarchy is not created as KSP wants it. I just missed that detail, the problem was happening because when you import a DAE, you have the following hierarchy:

• RenderLayers
• World
• Camera
• Lamp
• MeshName (Mesh Object)
  • yada yada
  • yada
• MeshName.collider (Mesh Object)
  • yada yada
    +yada

To fix the problem, you need to create a hierarchy like this:

• RenderLayers
• World
• Camera
• Lamp
• GameObject (create as empty object)
  • PartName (create as empty object)
    • MeshName (Mesh Object from DAE)
      • yada yada
      • yada
    • MeshName.collider (Mesh Object from DAE)
      • yada yada
      • yada

And that's it!! Problem solved!!! :D

The io_object_mu is not criticising the inputs, so it ended up blindly using the wrong object on the create_animation function because the expected hierarchy was not found, but the thing ignored the problem and kept going.

Concrete Use Case:

This is the II-hydrogenIsotopeConverter/model.dae after being imported into Blender:

And this is the same Part after being "converted":

Note to my future self: when converting DAEs, you need to create a new Collider Object using the mu Tools. Whatever you get from the DAE as a collider, will not work! :P

1. Create some simple collider using this menu:

2. Then replace the mesh with the one from the DAE's collider.

Oukey, both parts fixed. No more explosions, colliders work and they are clickable now. :)

Note to myself: FireSpitter has this issue too on the landing gears - can be completely unrelated, but worths to mention so I don't forget in the future.

Not sure yet, but this can be a nice hint. A vessel made of a unique Hydrogen Tank was launched, and this was found on the Player.log (but not on the KSP.log)

Physics.ClosestPoint can only be used with a BoxCollider, SphereCollider, CapsuleCollider and a convex MeshCollider.

(Filename:  Line: 1065)

[Untitled Space Craft]: ground contact! - error. Moving Vessel  up 999.177m

(Filename: /Users/builduser/buildslave/unity/build/artifacts/generated/common/runtime/DebugBindings.gen.cpp Line: 51)

Unpacking Untitled Space Craft

(Filename: /Users/builduser/buildslave/unity/build/artifacts/generated/common/runtime/DebugBindings.gen.cpp Line: 51)

Non-convex MeshCollider with non-kinematic Rigidbody is no longer supported in Unity 5.
If you want to use a non-convex mesh either make the Rigidbody kinematic or remove the Rigidbody component. Scene hierarchy path "II-hydrogenTank (Untitled Space Craft)/model/node_collider", Mesh asset path "" Mesh name "Cylinder_003-mesh"

There is a "Cylinder_003-mesh" object on the Hydrogen tank mesh file. So, things are making sense.