I am getting this error on a carbon server, running the latest dedicated server and carbon versions. What is causing this error?

Failed to call internal hook 'OnPlayerRespawned' on plugin 'Backpacks v3.13.5' [458523914] (Object reference not set to an instance of an object.)
at void Oxide.Plugins.Backpacks.OnPlayerRespawned(BasePlayer player) in /home/container/carbon/plugins/Backpacks.cs:line 418
at object Oxide.Plugins.Backpacks.InternalCallHook(uint hook, object[] args) in Backpacks.cs/Internal:line 626

This means a hook was called by the modding framework with an invalid player. This could be a bug in the modding framework, or another plugin triggering the hook directly in a way that doesn't conform to standard behavior, or it could just be an edge case that happens in vanilla which isn't handled by the plugin. In all cases, this has no impact.