Hello. AC is looking for a driver file called "driver_pudding"
as specified in the driver3d.ini file.
To fix this you can modify the file. You will find it in the ...steamapps\common\assettocorsa\content\cars\legion_brm_type_15\data folder. Open it with Notepad, select everything in it, delete it, then copy this:
[MODEL]
NAME=driver_60
POSITION=0, 0, 0
[STEER_ANIMATION]
NAME=steer.ksanim
LOCK=360
[SHIFT_ANIMATION]
BLEND_TIME=100
POSITIVE_TIME=250
STATIC_TIME=100
NEGATIVE_TIME=250
PRELOAD_RPM=8800
INVERT_SHIFTING_HANDS=0
[HIDE_OBJECT_0]
NAME=DRIVER:HELMET_69_SUB1
[HIDE_OBJECT_1]
NAME=DRIVER:HELMET_69_SUB0
[HIDE_OBJECT_2]
NAME=DRIVER:GEO_Driver_FACE
[HEAD_MOVEMENT]
FILTER=0.150000
MAX_G=1.500000
ROLL_MAX_DEG=-8
PITCH_MAX_DEG=-7
YAW_MAX_DEG=12
To the line above and paste it in the driver3d.ini file. Save the file and then the car will load in AC.
I haven't driven it yet, but I'm looking forward to doing so. I have another BRM Type 15 mod, but I don't remember where I got it from now. It's labelled as 1951 with 525hp, although I don't think it is '51 as it still has an external exhaust pipe. The 350hp of this mod may be an earlier stage in the engine development...? Anyway, thanks for the link to the mod, the sound and graphics are good. Shame about the solid rear axle, but modelling a DeDion is a bit problematic in AC I suppose.