Hi Matadem, one of your curves is a little short, this could be what is causing problems doing a boolean with something created from it:





Also it kind of looks like there may be some duplicated faces in your ellipse solid.

For making a dome the rail revolve command (Construct > Revolve >Rail revolve) can be good for that:
https://moi3d.com/4.0/docs/moi_command_reference7.htm#railrevolve

You set up a side profile curve like this:



Then select the profile, run rail revolve, then at the "Select rail curve" prompt select the ellipse, then pick 2 points for the revolve axis.

I'll see about setting up your file like that shortly.

- Michael