Physics Asset Tool (PhAT) Crash, too many Physics Bodies

The Physics Asset Tool Editor will crash when the Physics Asset you will open has too many Physics Bodies.
The limit seems under 100.
This can reproduce with the Third Person template.

I also have this issue it crashes with a fatal error after adding too many physics bodies.

I seem to be able to add a lot more bones in UE4 4.18 preview 2. There seem to be a few changes with the physics asset tool.