(22:04:44) | [Oxide] 22:04 [Error] Failed to call hook 'TryForceRulerCmd' on plugin 'PoliticalSurvival v0.5.5' (KeyNotFoundException: The given key was not present in the dictionary.)
  at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <a8ed250850854b439cedc18931a314fe>:0 
  at Oxide.Plugins.PoliticalSurvival.SetRuler (BasePlayer ruler) [0x00080] in <c9a61e659fdb419b9d9222c1cba4c459>:0 
  at Oxide.Plugins.PoliticalSurvival.TryForceRulerCmd (BasePlayer player, System.String command, System.String[] args) [0x00056] in <c9a61e659fdb419b9d9222c1cba4c459>:0 
  at Oxide.Plugins.PoliticalSurvival.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00a0a] in <c9a61e659fdb419b9d9222c1cba4c459>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <41771c7bc8d246d0b0a34c2f0d27f2cb>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <b0a93b504f034a0db8b1c3d2503c0987>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <b0a93b504f034a0db8b1c3d2503c0987>:0

This should now be fixed in v0.5.7

(07:52:06) | [Oxide] 07:51 [Error] Failed to call hook 'ClaimRuler' on plugin 'PoliticalSurvival v0.6.3' (KeyNotFoundException: The given key was not present in the dictionary.)
at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <a8ed250850854b439cedc18931a314fe>:0
at Oxide.Plugins.PoliticalSurvival.SetRuler (BasePlayer ruler) [0x00091] in <3859d2bf4f604e9183b68e9d161dd26c>:0
at Oxide.Plugins.PoliticalSurvival.ClaimRuler (BasePlayer player, System.String command, System.String[] arguments) [0x00044] in <3859d2bf4f604e9183b68e9d161dd26c>:0
at Oxide.Plugins.PoliticalSurvival.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00cf6] in <3859d2bf4f604e9183b68e9d161dd26c>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <efb9a8684e344ecfa065c7b416e6d2fd>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <b0a93b504f034a0db8b1c3d2503c0987>:0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <b0a93b504f034a0db8b1c3d2503c0987>:0

That is not the same error. But will investigate the cause 

fixed in v0.7.0

Thank you :)