What might cause this? We installed Oxide.Ext.Discord and restarted the server - tried to coinnect the bot-authenticator but no go, returns this error.

oxide.reload DiscordConnect

DiscordConnect was compiled successfully in 1765ms

Unloaded plugin Discord Connect v1.0.6 by Iv Misticos

Failed to initialize plugin 'DiscordConnect v1.0.6' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Ext.Discord.DiscordObjects.Channel.GetChannel (Oxide.Ext.Discord.DiscordClient client, System.String channelID, System.Action`1[T] callback) [0x00001] in <8623905c616349b49594ebac36d5c08b>:0 
  at Oxide.Plugins.DiscordConnect.Init () [0x000c6] in :0 
  at Oxide.Plugins.DiscordConnect.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0007e] in :0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9affce1cd15c4ec183941adef8db1722>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <4452f821def6406d834e4149849fe7ea>:0 
  at Oxide.Core.Plugins.CSPlugin.HandleAddedToManager (Oxide.Core.Plugins.PluginManager manager) [0x00043] in <4452f821def6406d834e4149849fe7ea>:0 

Unloaded plugin Discord Connect v1.0.6 by Iv Misticos

No previous version to rollback plugin: DiscordConnect

[Discord Ext] [Debug] Unhandled event: PRESENCES_REPLACE

Thanks for your report.

After the latest patch where i uninstalled the old version and installed the new one - i get another error. The following 

oxide.reload DiscordConnect

Unloaded plugin Discord Connect v1.0.7 by Iv Misticos

Failed to initialize plugin 'DiscordConnect v1.0.7' (LimitedClientException: Error! You may only use one apikey/client per plugin!)
  at Oxide.Ext.Discord.Discord.CreateClient (Oxide.Core.Plugins.Plugin plugin, Oxide.Ext.Discord.DiscordSettings settings) [0x0009f] in <8623905c616349b49594ebac36d5c08b>:0 
  at Oxide.Ext.Discord.Discord.CreateClient (Oxide.Core.Plugins.Plugin plugin, System.String apiKey) [0x0002e] in <8623905c616349b49594ebac36d5c08b>:0 
  at Oxide.Plugins.DiscordConnect.Loaded () [0x0005d] in :0 
  at Oxide.Plugins.DiscordConnect.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x000e5] in :0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9affce1cd15c4ec183941adef8db1722>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <4452f821def6406d834e4149849fe7ea>:0 
  at Oxide.Plugins.CSharpPlugin.HandleAddedToManager (Oxide.Core.Plugins.PluginManager manager) [0x0006e] in <9affce1cd15c4ec183941adef8db1722>:0 

Unloaded plugin Discord Connect v1.0.7 by Iv Misticos​

Even if the plugin only uses 1 apikey.. 
I have DiscordStatus installed which is working perfectly. Tried to uninstall that one and installing DiscordConnect again - giving it another 

"Channel ID For Authentication Log":

But not working

LimitedClientException may be an extension issue thn. Make sure you entered correct Channel ID and bot can access it. It may not work only in one case in my opinion - discord extension issue. I have no idea why wouldnt it else. I will move all channels, etc without optimization and see if it fixes that, huh?

Did you restart your server? That error usually means, restart the server.

Thanks for the tip - i will try it when i get home from work.