The mod crashes FabricASM (if it is installed) on startup, breaking other mods that require the use of FabricASM.
It looks like BackPacked doesn't use FabricASM anymore, removing "mm:early_risers" from fabric.mod.json should fix the issue.

latest.log
The log is attached, Backpacked wasn't the source of the crash, but when loading, the FabricASM (called MM) crash from Backpacked can be seen.