I don't understand what you mean by that, sorry.

I think it crashes when the BloodMagicHelper class is loaded (https://github.com/InfinityRaider/AgriCraft/blob/429f12750847ea51547042b5cceeca83ad1bad58/src/main/java/com/InfinityRaider/AgriCraft/compatibility/bloodmagic/BloodMagicHelper.java#L18) to find out if its methods should be called, thusly I have replaced the direct referencing with reflection, should fix the problem. Feel free to reopen this if it persists.

You need to add an @Optional.Interface for IHarvestHandler in the class you're loading (or not load that class), otherwise the mod will crash if the IHarvestHandler class from AlchemicalWizardry (whatever that is!?) is not present. Like it did for me.

But it is there though:
https://github.com/InfinityRaider/AgriCraft/blob/master/src/main/java/com/InfinityRaider/AgriCraft/compatibility/bloodmagic/BloodMagicHarvesthandler.java#L10

Thanks a lot. I am fiddling with AgriCraft 1.4 for my pack and am excited for the improvements! \o/

Yes the improvements I've been working on were more than necessary