Something didn’t work? Send us what happened, the log and the blueprint — they tell us exactly why.
C:\Program Files (x86)\Steam\userdata, then your number folder, then 3493540 → local → crash_dump.stdout.txt from there. It has everything we need, including your list of mods.TransportFever2.exe.blueprint_exchange_log.txt, and if it is about one of your own blueprints, its blueprint_<name>.lua.Your private edit key is removed from the file before it is sent — nobody but you can ever update your blueprint.
Only plain text is accepted (.txt and .lua, nothing that can run). Reports are private: only the BPX team can read them. Prefer to talk it through? The community forum is open too.