'RustCore v2.0.5925' is using deprecated hook 'OnMapMarkerRemove', which will stop working on Sunday, 31 December 2023. Please ask the author to update to 'OnMapMarkerRemove(BasePlayer player, List<MapNote> mapMarker, int index)'

"RustCore" is where the issue lies, and that's Umod's Rust Extension..hence..the "Core" in it.  LOL

It's known, and will be patched in time.  They've already stated that.

Failed to call hook 'CanNetworkTo' on plugin 'TcMapMarkers v1.1.2' (InvalidCastException: Null object cannot be converted to a value type.)
  at System.Convert.ChangeType (System.Object value, System.Type conversionType, System.IFormatProvider provider) [0x00019] in <e3aa8db986d7457ca73f10110f1283f5>:0

  at System.Convert.ChangeType (System.Object value, System.Type conversionType) [0x00007] in <e3aa8db986d7457ca73f10110f1283f5>:0

  at Oxide.Core.Plugins.Plugin.Call[T] (System.String hook, System.Object[] args) [0x00008] in <beb2b64691c64e2b95b99491bd85442c>:0

  at Oxide.Plugins.TcMapMarkers.CanNetworkTo (MapMarkerGenericRadius marker, BasePlayer player) [0x00123] in <54001f7e48c340c081690ece923d4ad6>:0

  at Oxide.Plugins.TcMapMarkers.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00240] in <54001f7e48c340c081690ece923d4ad6>:0

  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <795304323ac74a298b8ed190a1dfa739>:0

  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <beb2b64691c64e2b95b99491bd85442c>:0

  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <beb2b64691c64e2b95b99491bd85442c>:0