Minecraft 1.16.4
Forge 35.1.36
Transport 3.4.0

When trying to load my singleplayer world, I get this screen:
"Errors in currently selected datapacks prevented world from loading. You can either try to load only with vanilla datapack ("safe mode") or go back to title screen and fix it manually"
When I downgrade Transport to 3.3.1, it loads fine.

debug-4.log

Looks like Registrate isn't a fan of you turning off the steam bucket Sky...
Could be cross mod interaction with Thermal's bottler too

Same issue on world creation:
https://paste.ee/p/1KIxE

This seems like the right place to leave these:
latest.log
crash-2021-01-12_07.39.24-client.txt

With an existing world I get the datapack error (not sure if that's your fault; it seems to happen whenever I update mods). With a new world it crashes with an error related to steam buckets.

Hello, confirmed here as well, on world creation after adding the following mods:
rftoolsX/rsrequestify/sophisticatedbackpacks/thermalX/tubesreloaded/xnet/xnetgases/mcjtylib

Should I remove transports or thermalX mods for now, or does it matter? thanks

Crash Report: https://pastebin.com/WA5Wvm8V

I put a link to this on the Team CoFH Discord so that they are aware as well.

The error here seems to be that Transport is not registering their Steam Bucket, but is telling the fluid that it has.

Yep it's on my side. Working on a fix.

Going back to 3.3.x is a fix for now.

Ah yes I just had this error, thank you @SkySom for saying what the fix would be.

Yep no problem. My hope is to get a fix out tonight.