Hello,
Since the new version of Realistic Electric trains (0.4), Tiers 32 errors out on loading Factorio:
https://i.imgur.com/itBkKgt.png
I also talked with the author of that mod who said:
Regarding the crash, I looked at that mod's code and it appears to be an issue with that mod. It does not check, if the input/output flow rates of a battery equipment (which I used as the base items for my modules) is actually set. I used the default value of nil (should be treated as zero), which then causes some issues.
Source: https://mods.factorio.com/mod/Realistic_Electric_Trains/discussion/5c966f8f5b139d000be32d4c
I'd like to note that Tiers 32 worked nicely with Realistic Electric Trains version 0.3.2 but not with version 0.4.