Good Morning at all!

I'm sorry for such trivial question, but I'm new entry here and I've started using this softare few days ago.

I'm trying to reproduce a DOL start of a 3-phase asyncronous squirrel cage motor.
I'm able to start the simulation without any problem, linking the sine source to the motor and the load. Once I insert the 3-phase ideal closing switch bewteen source and the motor /having its own terminal box) the system becomes undertermined. I sincerly don't know how to solve the problem which is due to the last inserted block, the 3-phase switch.

I've just tried to reproduce for my own the shown example.
Thank you in advance for your support.

Vincenzo