The best way to dig and locate problematic mod is by reading and investigating the game log (through file or dev console). You can't rely on indicators given by game's Mod Manager.

madman a écrit :

The best way to dig and locate problematic mod is by reading and investigating the game log (through file or dev console). You can't rely on indicators given by game's Mod Manager.

Ooookay.....ummm any idea what I should be keeping an eye out for? Sorry I'm not very familiar with coding or what to look for.

If it crashes at the dealer it's most likely a truck mod, or truck parts.
Paint jobs usually aren't problematic, but if it's an old one, somewhere around pre version 1.36 then the cause for trouble with paint jobs is higher, there is of course a chance that it's a more recent one with (an) error(s) in it :-)

Usually when you open the game log right after a crash the cause is in the last few lines, just in case on a default win 10 install the game.log.txt can be found here:
C:\Users\YOURNAMEHERE\Documents\American Truck Simulator

For other trouble shooting and finding mods with problems it's easier to use the in game console as warnings and errors are in a different colour (yellow and red)
Just in case here's Squirrels video about the console, how to enable it and other things you can do (it's a little bit outdated, but the important bit on how to open the console still works:
https://youtu.be/DSMecKfmubo

edit: Sometimes the load order is a cause for trouble.

Thanks a ton that was really helpful. I'll let you know if I find it & I'll name the mod (if it's that & not the load order) so other people can watch out for it. Just in general what's the safest Load Order to list mods in. I know I've seen World textures say they should be at the top of the list, what would be below them etc. Can sound files be placed anywhere?

Here's what the report says if it helps out.

00:06:54.515 : <ERROR> [traffic] Error finding a suitable traffic_vehicle data variant of type 'police' (custom filter)
00:06:54.515 : <ERROR> [parked_vehicle] "No suitable vehicle model found!" [-84925.2;30.6;5836.4]
00:07:14.479 : <ERROR> [unit] File '<C:/SteamLibrary/steamapps/workshop/content/270880/781091063/universal.zip | >/ui/dashboard/kenworth_w900.sii', line 3:
00:07:14.479 : <ERROR> [unit] The unit name 'w900_main' is already taken by an existing unit (of type 'ui::window').
00:07:14.479 : <ERROR> load_unit_tree() - Failed to load unit tree from file (/ui/dashboard/kenworth_w900.sii)
00:07:14.479 : <ERROR> Failed to load ui script '/ui/dashboard/kenworth_w900.sii'
00:07:23.151 : <WARNING> [di8] Input buffer overflow for device 'mouse' (error code: 0x1).
00:07:23.159 : <WARNING> [di8] Input buffer overflow for device 'mouse' (error code: 0x1).

I guess we can't use that local police vehicle livery mod & something wrong with the Kenworth w900 mods. A shame since I really liked that Police one....weird how it didn't cause a crash upon loading the world though. : /

Okay so I removed ANY & all Kenworth w900 mods that I had installed & I thought that would fix it. Oddly enough I saw one listed in my fav/subscribed list that I don't even remember seeing in the IN GAME list along the lines of Kenworth w900 LONG which again, was never viewable in the in game mod list but was listed on STEAM under my favs/subs mods. Anywho here's what popped up after I found that one & tried installing it along with other w900 mods since removing those didn't fix my issue.

00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.19A9.85B8' (of type 'vehicle_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.19A9.6878' (of type 'vehicle_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.19A9.5EF8' (of type 'vehicle_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.19A9.5D38' (of type 'vehicle_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.19A9.9078' (of type 'vehicle_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.19A9.5578' (of type 'vehicle_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.19A9.55B8' (of type 'vehicle_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.ftire' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.fdisc' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.fhub' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.fnuts' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rtire' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rdisc' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rhub' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rnuts' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rtire2' (of type 'vehicle_wheel_accessory').
00:04:22.320 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rdisc2' (of type 'vehicle_wheel_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rhub2' (of type 'vehicle_wheel_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rnuts2' (of type 'vehicle_wheel_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.1938.D1B0' (of type 'vehicle_paint_job_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.1433.A430' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.steeringw' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.bumper' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.cabdefl' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.exhaust' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.filter' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.mudflaps' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.rear_cab' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.tank' (of type 'vehicle_addon_accessory').
00:04:22.321 : <WARNING> Ignoring obsolete attribute 'wear' of unit '.int_9800d.trlr_cables' (of type 'vehicle_addon_accessory').
00:04:22.326 : <WARNING> [model] Model animation '/vehicle/truck/inter.9800/wipers.pma' has incorrect file version 4 - expected version 5. Converting...
00:04:22.327 : <WARNING> [model] Model animation '/vehicle/truck/inter.9800/win_open_l.pma' has incorrect file version 4 - expected version 5. Converting...
00:04:22.328 : <WARNING> [model] Model animation '/vehicle/truck/inter.9800/win_open_r.pma' has incorrect file version 4 - expected version 5. Converting...
00:04:22.331 : <WARNING> Ignoring obsolete attribute 'wheel_anim' of unit 'standard.internat9800.interior' (of type 'accessory_interior_data').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.data' (of type 'vehicle_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.chass' (of type 'vehicle_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.cab' (of type 'vehicle_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.int' (of type 'vehicle_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.eng' (of type 'vehicle_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.trans' (of type 'vehicle_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.light' (of type 'vehicle_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.paint' (of type 'vehicle_paint_job_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.skoda.mirror' (of type 'vehicle_addon_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.ftire' (of type 'vehicle_wheel_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.rtire' (of type 'vehicle_wheel_accessory').
00:04:22.519 : <WARNING> Ignoring obsolete attribute 'wear' of unit '_nameless.f_mirror' (of type 'vehicle_addon_accessory').
00:04:22.524 : <WARNING> [model] Model animation '/vehicle/truck/skoda_superb/wipers_eu.pma' has incorrect file version 3 - expected version 5. Converting...
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'low_beam_sign_color' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'low_beam_sign_range' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'low_beam_attenuation' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'hi_beam_sign_color' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'hi_beam_sign_range' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'front_beam_sign_color' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'front_beam_sign_range' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'roof_beam_sign_color' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'roof_beam_sign_range' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'front_roof_beam_sign_color' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:22.534 : <WARNING> Ignoring obsolete attribute 'front_roof_beam_sign_range' of unit 'xenon.marin.kart.head_lights' (of type 'accessory_head_lights_data').
00:04:29.147 : <ERROR> load_unit() - Expected exactly one top-level unit in file (/def/vehicle/truck/kenworth.w900/interior/exclusive.sii), got 2
00:04:29.214 : <ERROR> load_unit() - Expected exactly one top-level unit in file (/def/vehicle/truck/kenworth.w900/interior/standard.sii), got 2
00:04:29.490 : <ERROR> [unit] File '<C:/SteamLibrary/steamapps/workshop/content/270880/781091063/universal.zip | >/ui/dashboard/kenworth_w900.sii', line 3:
00:04:29.490 : <ERROR> [unit] The unit name 'w900_main' is already taken by an existing unit (of type 'ui::window').
00:04:29.490 : <ERROR> load_unit_tree() - Failed to load unit tree from file (/ui/dashboard/kenworth_w900.sii)
00:04:29.490 : <ERROR> Failed to load ui script '/ui/dashboard/kenworth_w900.sii'

What do you all think this means?

Alright so I figured it out, the mod called "Kenworth W900 Blue Interior" is what was causing the crash. It seems it's not supported or updated anymore which is a shame since I really liked that color....oh well.