Description:

• Game starts up fine, but will crash when loading into a single player world.

Steps to Reproduce:

• Import/install modpack on Curseforge: here
• Open a singleplayer world
• feel anguish as your minecraft disintegrates

Technical Information:

• Minecraft: 1.16.5
• Fabric API: fabric-api-0.42.0+1.16.jar
• Fabric Modloader: 0.12.11
• Industrial Revolution: indrev-1.9.18-BETA.jar
• Modpack: (Unofficial) death by sandwich

Logs:

• pastebin.com

Details:
not 100% certain indrev causes the crash but the crashlog said something about indrev so here i am

Thanks for reporting, sadly IR is not receiving updates for 1.16.5 anymore. This was an old conflict between NBTCrafting mod and IR which has already been fixed in later versions.