I didn't save the Last game, but the same erro has happened twice more, and I got a save game this time.
Neutrals were switched off.
I left SE4 too, even though it said '[not responding] after 2 minutes (cntrl+alt+delete).
Also, I noticed the bubble gel armour stuff has a size of 0kt Zero. That could be a prob. I was thinking the nano-bots for HBUM has a size of 1kt (and seemed to be the source of a similar error), maybe SE4 AI doesn't like components smaller then 10Kt?
Oh, and I re-made the battle, because I thought it bit boring just to copy a moon. '
' - Hope someone likes it.