**CARBON** - Error in console on update

Hi there! 

I recently updated this plugin and noticed that Im getting an error in the console. 
Players are also reporting that portable lockers is currently unavailable in game. 

Heres the error :

Failed to call internal hook 'OnServerSave' on plugin 'PortableLocker v1.5.0' [2396958305] (Object reference not set to an instance of an object)
   at void Oxide.Plugins.PortableLocker.SaveContainer() in /home/container/carbon/plugins/PortableLocker.cs:line 619
   at void Oxide.Plugins.PortableLocker.OnServerSave() in /home/container/carbon/plugins/PortableLocker.cs:line 332
   at object Oxide.Plugins.PortableLocker.InternalCallHook(uint hook, object[] args) in PortableLocker.cs/Internal:line 106

Thanks in advance!