Not opening in zones with "NoPlayerLoot" flag, conflict with DC Protect
Wont open in zones with flag "No player loot" Also fights plugin DC protect with errors for looting another player when opening your own. Hope this helps.
When posting issues, please provide details such as logs, errors, etc. so that we're able to help you.

(15:49:07) | Calling hook CanLootPlayer resulted in a conflict between the following plugins: DCProtect - False (Boolean), Backpacks (True (Boolean))

(15:49:07) | [DCProtect] Player 17|Zach tried to loot 17|Zach after the server started...tisk tisk.

As for the zone looting issue, it just gives the notice your not allowed to loot in this area when you try to open backpack

That conflict warning shows because one plugin is telling Oxide that the player can loot, the other is saying they can't. Backpacks should probably be not returning anything if they want to allow it, but that may result in undesirable behavior. The plugin may have to integrate with Zone Manager to fix the other issue.
Yep we reverted to the old plugin for now. Just posting so the dev knows.