Solved the problem (I hope). I loaded the mod "Kuky's Better Fire, Smoke, & Explosions" from our site since it gives a much better picture of these events and helps to ID these from farther away in combat. Then I noticed another on our site "Kuky's Smoke Mod" that Increases the burn time and amount of smoke for destroyed vehicles. That overwrote Firevehicle.lua in DCS World\Bazar\ParticleEffects\Effects. I put the one from the first mod back in and last night had no crashes in multiplayer.
Who'd a thunk it?
If anyone has not installed either of these mods and has the original files, please let me know. I didn't keep them and would like to do so just in case. Looking for:
DCS World\Bazar\ParticleEffects\effects\FireVehicle.lu a
DCS World\Bazar\ParticleEffects\effects\FiatSmokeCloud .lua
DCS World\Bazar\ParticleEffects\textures\DCSFireTex.pn g
DCS World\Bazar\Effects\expl\boom1.lua