Having the same issue on my dedicated server since update and just found the solution:
Go to sandbox options > Loot Rarity > Other, set this to Normal. Reboot game/server if needed. You should no longer get errors when you enter search mode by now.
This is also why deleting the zomboid folder kinda solves the issue: doing so wipes all your settings, thus reset your sandbox options to default. Seems for whatever reasons, changing this option will cause foraging errors after the lastest update.