Yeah, that deals with the colour error, but not the other, (unknown variable l_owner). BTW I don't think this is a mirv problem, I haven't downloaded it yet! Just using v0.90d and Kae_shn sections, HM_Rocketbits. Get lots of other errors too, I'll root through some other threads to see if I can find anyone else with the same ones.
May have found an solution to this one and some others which seem to have the same cause.
Unknown variable l_bullet
Unknown variable image_angle
Unknown variable l_owner
Unknown variable l_syshp
Unknown variable l_cm1
Basically I got a continuous stream of these related to various sections, weapons, etc. etc. These seem to be caused by saving in SM whilst trigger lines, parenting lines etc. are disabled. I was experimenting with various things to try and find the problem and noticed it didn't happen when I hadn't turned lines off. Hope this works for you too, unless you're entering your ship in limited realism in the BP in which case ignore everything I just said, there is no solution, your ship will never work

. Mods, if this is posted in the wrong thread, sorry!