Hey it worked!

Basically I did as you all said and selected the dome object.
Then I went into /Modify Panel/ and activated /Sub-Edge/ selection.
Selected all of the edges of the dome, /Ignore Backfacing/ was disabled.
Scrolled down into /Surface Properties/ rollout and clicked on /Visible/(still I couldn’t see the edges of the deselected dome even with the /Edged Faces/ on.
Then set /Auto-Edge/ value to 1.0 and clicked it, the dome was an Editable Mesh still.
Converted the dome to /Editable Poly/, with no issues.
After that I did the /Boolean/ on the dome and /Union(ed)/ it with the box object.

Uber Thanks!

Try “Convert to Poly” on it before doing the Visible / AutoEdge. I for one would like to know why having hidden edges would cause that kind of corruption.

Take a simple sphere converted to Editable Mesh, make the edges invisible then convert to poly. Something is wrong somewhere - a bug maybe? or is that behaviour “expected”?

Steve, I believe it has something to do with the Editable Poly conversion trying to read faces as polys, and with the hidden edges it tries to make a Poly out of just visible edges.  I’ve seen that happen before.

3DS Max Design 2011 64-bit - Advantage Pack
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