Hmm, I can't seem to trigger it myself... at what point does the crash occur? It won't trigger for me with either mod variant, placing the planner, upgrading it to track, bulldozing it, etc.

Is this with the metric or imperial mod variant? The error it's reporting is on a line I tweaked for the imperial one, but in neither case does it affect or access anything to do with cost - it's just the line calculating the speed limit text.

Are these the only two mods you have loaded?

Hmm, looking further through the log file, it does look like you've got an extensive list of mods running there.
Line 115 makes reference to the trackType parameter - with a fixed two options in my mod:
0 - "standard.lua"
1 - "high_speed.lua"
- and the error suggests it's attempting to index a field that doesn't exist... perhaps meaning something is trying to make it pick an index higher than 1... that shouldn't be possible, as there's only ever those two buttons available, and I even have a pre-check before launching the construction options to ensure that even any un-set values get set to a default of 0 instead of nil.

One thing I'm wondering about is the commonapi mod. I haven't tried it, so I've no idea how it works, but the impression I get is that it gets its fingers in fairly deep, and tries to make things like modded track types, etc, available to other mods.
Does it look like anything is nudging my mod to have more available track types than those two vanilla ones?

It's possible I could work in a catch that'll pre-check whether an entry is in-range or clamp the value, if I can work out roughly what might be triggering it in the first place.


Of course the other thing could be, if you've got any mods in there that override or somehow remove those two default track styles, *could* be messing with things.