After wipe today we started seeing:

[Oxide] 20:05 [Error] Failed to call hook 'OnPlayerSleepEnded' on plugin 'GUIAnnouncements v2.0.6' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.GUIAnnouncements.OnPlayerSleepEnded (BasePlayer player) [0x00014] in <a7a337f02392404b8eb4b639762adfc1>:0

  at Oxide.Plugins.GUIAnnouncements.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00892] in <a7a337f02392404b8eb4b639762adfc1>: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

(22:08:45) | Failed to call internal hook 'OnPlayerSleepEnded' on plugin 'GUIAnnouncements v2.0.6' [3025469128] (Object reference not set to an instance of an object)

at void Oxide.Plugins.GUIAnnouncements.OnPlayerSleepEnded(BasePlayer player) in /home/rustserver/serverfiles/carbon/plugins/GUIAnnouncements.cs:line 1193

at object Oxide.Plugins.GUIAnnouncements.InternalCallHook(uint hook, object[] args) in GUIAnnouncements.cs/Internal:line 421

(22:08:28) | Failed to call internal hook 'OnEntityDeath' on plugin 'GUIAnnouncements v2.0.6' [1779071345] (Object reference not set to an instance of an object)

at void Oxide.Plugins.GUIAnnouncements.OnEntityDeath(BaseCombatEntity entity) in /home/rustserver/serverfiles/carbon/plugins/GUIAnnouncements.cs:line 1814

at object Oxide.Plugins.GUIAnnouncements.InternalCallHook(uint hook, object[] args) in GUIAnnouncements.cs/Internal:line 363

Failed to call hook 'OnEntityDeath' on plugin 'GUIAnnouncements v2.0.6' (NullReferenceException: Object reference not set to an instance of an object)
at Oxide.Plugins.GUIAnnouncements.OnEntityDeath (BaseCombatEntity entity) [0x001d0] in <661c01d3af754794971bfc53ddcdee93>:0
at Oxide.Plugins.GUIAnnouncements.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x009b1] in <661c01d3af754794971bfc53ddcdee93>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <206a0f2c6ee141f38e2ad549cde44d70>: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

Same thing.  This plugin desperately needs an update.  Is it still being developed or is it abandoned?? 

Looks like this was abandoned. Sad too because a lot of people use it. getting more errors now