Having the same issue, even when the player is not near or offline
KeyNotFoundException: The given key '76561199467393427' was not present in the dictionary.
at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <8ce0bd04a7a04b4b9395538239d3fdd8>:0
at Oxide.Plugins.TalkingNpc+ConversationHandler.EndConversation (BasePlayer player, System.Boolean endConversation) [0x00033] in <c8d9cdf884fd4f46ad38915d03f1465b>:0
at Oxide.Plugins.TalkingNpc+ConversationHandler.CheckPlayersWalkAway () [0x0006e] in <c8d9cdf884fd4f46ad38915d03f1465b>:0
at InvokeHandlerBase`1[T].DoTick () [0x00138] in <97363e0bbe864c65a9819cff9eddaf42>:0
at InvokeHandlerBase`1[T].LateUpdate () [0x0000c] in <97363e0bbe864c65a9819cff9eddaf42>: