After so long, the same thing happens to me.
I have installed msphysics on many other machines and have never had this problem.
Specifically on this laptop I have tested Sketchup 16 and 18, and it happens as seen.
Anton, thank you very much, the plugin is wonderful.
It would also be interesting if it allows solving situations like this:
In the previous drawing the circles O1 and O2 are known
I mean to draw an arc tangent to two circles.
Like in the image.
Is it possible to draw an arc tangent to two others?
Thank you very much
Again, thanks Anton, I have managed to give life to my creature 
Resolved. Thank you thank you thank you
@anton_s said:
tecnozati,
Yeah, the docs do not have enough coding examples. But I intended to fix that someday.
To get the position of a servo joint from a script field, you will first need to know the name/id of the joint, which is displayed in UI when you select the joint. Then you can write the following code:
> onStart {
> @j = simulation.find_joint_by_name("569422")
> }
>
> onTick {
> # Set desired angle
> if (key(' ') == 1)
> @j.controller = 100.degrees
> else
> @j.controller = 0
> end
>
> # Get current angle
> simulation.log_line @j.cur_angle.radians
> }
>
You can refer to servo docs for more functionality: https://www.rubydoc.info/github/AntonSynytsia/MSPhysics/MSPhysics/Servo
Anton
Thank you, thank you, thank you! The head was going to burn me!
And above all, thanks for Msphysics! 
Hello everyone, to see if a charitable soul can help me out.
Using MSPhysics script I want to get:
1 know the position of a servo join
2 move the servo without using “get_var ()” as controller
I wish to animate a mechanism with scripting, I would greatly appreciate code examples (I find it almost impossible to find them)
Greetings and many thanks