Hello, I run a carbon server and downloaded the Spawn Modular Car plugin today, I am running the latest version of the dedicated server and carbon. I am getting this spammed in console. Any idea why this is happening?

Failed to call internal hook 'OnEntityKill' on plugin 'SpawnModularCar v5.3.0' [304634108] (Object reference not set to an instance of an object)
at bool Oxide.Plugins.SpawnModularCar.IsPlayerCar(ModularCar car) in /home/container/carbon/plugins/SpawnModularCar.cs:line 1948
at void Oxide.Plugins.SpawnModularCar.OnEntityKill(ModularCar car) in /home/container/carbon/plugins/SpawnModularCar.cs:line 169
at object Oxide.Plugins.SpawnModularCar.InternalCallHook(uint hook, object[] args) in SpawnModularCar.cs/Internal:line 297
Failed to call internal hook 'OnEntityKill' on plugin 'WaterBases v1.0.20' [304634108] (Object reference not set to an instance of an object)
at void Oxide.Plugins.WaterBases.OnEntityKill(SimpleShark shark) in /home/container/carbon/plugins/WaterBases.cs:line 651
at object Oxide.Plugins.WaterBases.InternalCallHook(uint hook, object[] args) in WaterBases.cs/Internal:line 234

It looks like something is wrong with your server which is causing invalid entities to be killed, and seems it's causing errors in other plugins as well such as Water Bases.

any idea what would be causing that to happen?

Not really. I can only speak to what is happening on the plugin side, which is that it's observing these calls that shouldn't be happening in the first place.