Mounting Units in BI

[RTW King]

Why cant I mount units in BI? I tried to mount several kinds of soldiers but the game crashes when its starting up. I'm sure I did it the exactly the same way as in RTW, I only needed to change the descr_model_battle and export_descr_unit files. I transported a unit model from RTW to BI and I successfully created an infantry version. I then tried to mount it. This is what I typed into descr_model_battle:

type barb_infantry_longshield_cav
;--------------------------------------
skeleton fs_hc_spearman, ; combat spear
indiv_range 40
texture alemanni, data/models_unit/textures/Z_ALEMANNI_SPEARMEN.tga
model_flexi data/models_unit/unit_barb_warband_longshield_high.CAS, 8
model_flexi data/models_unit/unit_barb_warband_longshield_med.cas, 15
model_flexi data/models_unit/unit_barb_warband_longshield_low.cas, 30
model_flexi data/models_unit/unit_barb_warband_longshield_lowest.cas, max
model_sprite alemanni, 60.0, data/sprites/empire_west_sarmatian_auxilia_sprite.spr
model_tri 400, 0.5f, 0.5f, 0.5f

For export_descr_unit, I typed:

type barb infantry gaul
dictionary barb_infantry_gaul3 ; Alemanni Mounted Spearmen
category cavalry
class light
voice_type Light_1
soldier barb_infantry_longshield_cav, 27, 0, 1.2
mount light horse
mount_effect elephant -4, camel -4
attributes sea_faring, hide_forest, can_swim
formation 3, 4, 6, 6, 4, square
stat_health 1, 0
stat_pri 7, 4, no, 0, 0, melee, simple, piercing, spear, 25 ,0.73
stat_pri_attr light_spear, spear_bonus_4
stat_sec 0, 0, no, 0, 0, no, no, no, none, 25 ,1
stat_sec_attr no
stat_pri_armour 3, 5, 6, flesh
stat_sec_armour 0, 0, flesh
stat_heat 3
stat_ground 2, -2, 3, 2
stat_mental 8, impetuous, untrained
stat_charge_dist 40
stat_fire_delay 0
stat_food 60, 300
stat_cost 1, 400, 200, 50, 70, 400
ownership alemanni

And for export_descr_unit_enums (although I don't know if this is relevant), I typed:

barb_infantry_gaul3
barb_infantry_gaul3_descr
barb_infantry_gaul3_descr_short

Please help me I'm working on a mod and this is really slowing me down.