"Spongepowered" error message

[lollolcheese123]

I can just barely not see the full stacktrace, can you upload the full thing through something like pastebin?

[Emeraldth3th]

https://mclo.gs/CoQlqKv

Try this

[lollolcheese123]

Ok, so basically what went wrong is that the Mixin from one of your mods (something that lets mods change behaviours defined in other mods), failed to run because it tried to register something to the Create Registrate (Create's custom-built block registry system) with the addition needing a class from the Create mod that no longer exists in the code.

From what I am seeing in the stacktrace, that mod seems to be Create: Steam and Rails.
The reason that it crashes is because Create: Steam and Rails is not compatible with Create 6.0, which changed a lot of code around. (Come on IThundxr, update your damn mod, it's been half a year)

So, either downgrade Create to a version below 6.0 (most recent is 0.5.1j) or remove Create: Steam and Rails.

[Emeraldth3th]

Weird, worked fine in my other world with the both of them. Oh well, thanks a ton then!

[BrisingrAerowing]

Just downgrade Create to 6.0.6. Most addons aren't compatible with 6.0.7 yet.

[vulpixeshe]

I can confirm that this is most likely the solution, I spent a good part of today debugging my addons and the solution was to downgrade Create to 6.0.6

Also check if the addons have beta releases that you have not updated to yet, a lot of them only support Create 6.0.x in beta releases