Harvesting does not work on unclaimed territory using GriefPrevention.

[jacob6707]

As stated in the title, harvesting crops does not work when outside a claim.
Once a claim is made and the player has permission to build inside the claim, the plugin works as intended.

From your implementation of canGriefPrev I see that you return false by default if the claim is null. Unless this is intentional, I believe returning true by default would fix the problem.