Try the following format i moved sprite model index to 7th param instead of the last. /** *TE_LIGHTNING is TE_BEAMPOINTS with simplified parameters * * @note * write_byte(TE_LIGHTNING) * write_coord(startposition.x) * write_coord(startposition.y) * write_coord(startposition.z) * write_coord(endposition.x) * write_coord(endposition.y) * write_coord(endposition.z) * write_short(sprite model index) * write_byte(life in 0.1's) * write_byte(width in 0.1's) * write_byte(amplitude in 0.01's) */