When I open the netherite_barrel at the coordinate position where y=0, put in a hopper, and upgrade it, the game crashed.

java.lang.NullPointerException: Cannot invoke "net.minecraftforge.common.util.LazyOptional.map(net.minecraftforge.common.util.NonNullFunction)" because the return value of "net.p3pp3rf1y.sophisticatedstorage.upgrades.hopper.HopperUpgradeWrapper.getItemHandler(net.minecraft.world.level.Level, net.minecraft.core.BlockPos, net.minecraft.core.Direction)" is null

crash report
latest

I am pretty sure I made significant changes in that part of code since that old version you have there. Please update and let me know if you're still experiencing the issue.

Thanks! Updating the mod fixed the issue. Wish you happiness every day!