Well - this is really quite strange. I've tried U.F.O. + the two mentioned other mods + Electric_flying_enemies and that loads without any problems. So I decided to make a test with razi + these mods and this combination fails – with a completely different error message:
Error while running setup for entity prototype "ufo-beacon" (beacon): next_upgrade target (omega-beacon) must have the same bounding box
After removing Electric_flying_enemies from the mod list, the load completes - as you can see here.
So it looks like that the combination of Electric_flying_enemies + razi + U.F.O. produces strange errors. I'll ask the author from Electric_flying_enemies, if he has an idea what might going on.