RedditSharp-DEPRECATED-: Doesn't work on Linux - mono

Removing all instances of RedditSharp clears errors and it works fine on my Windows PC.

I have no idea what the error means.

Unhandled Exception:
System.InvalidCastException: Specified cast is not valid.
  at RedditSharp.WebAgent.CreateRequest (System.String url, System.String method) <0x41fbdfc0 + 0x00177> in <filename unknown>:0
  at RedditSharp.BotWebAgent.CreateRequest (System.String url, System.String method) <0x41fbdec0 + 0x000b7> in <filename unknown>:0
  at RedditSharp.WebAgent.CreateGet (System.String url) <0x420396a0 + 0x00022> in <filename unknown>:0
  at RedditSharp.Reddit.InitOrUpdateUser () <0x42039400 + 0x0007b> in <filename unknown>:0
  at RedditSharp.Reddit..ctor (IWebAgent agent, Boolean initUser) <0x420390a0 + 0x00157> in <filename unknown>:0
  at botname.RedditAccount.startup () <0x41f936e0 + 0x000e3> in <filename unknown>:0
  at botname.Program.Start () <0x41f92150 + 0x000e3> in <filename unknown>:0
  at botname.Program.Main (System.String[] args) <0x41f90d50 + 0x00033> in <filename unknown>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.InvalidCastException: Specified cast is not valid.
  at RedditSharp.WebAgent.CreateRequest (System.String url, System.String method) <0x41fbdfc0 + 0x00177> in <filename unknown>:0
  at RedditSharp.BotWebAgent.CreateRequest (System.String url, System.String method) <0x41fbdec0 + 0x000b7> in <filename unknown>:0
  at RedditSharp.WebAgent.CreateGet (System.String url) <0x420396a0 + 0x00022> in <filename unknown>:0
  at RedditSharp.Reddit.InitOrUpdateUser () <0x42039400 + 0x0007b> in <filename unknown>:0
  at RedditSharp.Reddit..ctor (IWebAgent agent, Boolean initUser) <0x420390a0 + 0x00157> in <filename unknown>:0
  at botname.RedditAccount.startup () <0x41f936e0 + 0x000e3> in <filename unknown>:0
  at botname.Program.Start () <0x41f92150 + 0x000e3> in <filename unknown>:0
  at botname.Program.Main (System.String[] args) <0x41f90d50 + 0x00033> in <filename unknown>:0