Missing Method exception mono

Question

I want to execute my C# app, compiled in Windows, on my Ubuntu Server.

I am using the .Net Framework version 4.5 (can't change it cause of some 3rd party api's).

I have the most actual Mono version (2.10.8) for Ubuntu installed. My Application is compiled with VisualStudio 2012 on the Windows OS (7).

I am trying to make some Post requests to other websites and parse data. Here is the code which creates the Requests (which works on windows perfectly):

HttpWebRequest req = (HttpWebRequest)WebRequest.Create(uri.AbsoluteUri);

req.UserAgent = this.UserAgent;
req.CookieContainer = this.Cookies;
req.Referer = this.Location;
req.Host = uri.Host;
req.AllowAutoRedirect = false;

And the error i am getting from Mono comes here:

Unhandled Exception: System.MissingMethodException: Method not found: 'System.Net.HttpWebRequest.set_Date'.
  at manager.http.HttpBrowser.GetPostWebRequest (System.String url, System.Collections.Generic.Dictionary`2 postdata, System.Collections.Generic.Dictionary`2 headers) [0x00000] in <filename unknown>:0
  at manager.http.HttpBrowser.Post (System.String url, System.Collections.Generic.Dictionary`2 postdata, System.Collections.Generic.Dictionary`2 headers) [0x00000] in <filename unknown>:0
  at manager.http.HttpBrowser.Post (System.String url, System.Collections.Generic.Dictionary`2 postdata) [0x00000] in <filename unknown>:0
  at manager.networks.components.MyClass.MyMethod() [0x00000] in <filename unknown>:0
  at manager.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.MissingMethodException: Method not found: 'System.Net.HttpWebRequest.set_Date'.
  at manager.http.HttpBrowser.GetPostWebRequest (System.String url, System.Collections.Generic.Dictionary`2 postdata, System.Collections.Generic.Dictionary`2 headers) [0x00000] in <filename unknown>:0
  at manager.http.HttpBrowser.Post (System.String url, System.Collections.Generic.Dictionary`2 postdata, System.Collections.Generic.Dictionary`2 headers) [0x00000] in <filename unknown>:0
  at manager.http.HttpBrowser.Post (System.String url, System.Collections.Generic.Dictionary`2 postdata) [0x00000] in <filename unknown>:0
  at manager.networks.components.MyClass.MyMethod() [0x00000] in <filename unknown>:0
  at manager.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0

I googled for 2 days now and can't find a solution. :(

UPDATE:

The attributes set_Date AND set_host are currently not Implemented at Mono. (I upgraded my Version to 3.x)

Answer 1

.NET 4.5 is not supported in Mono 2.x, upgrade to Mono 3.x.

You have a guide here: Installing Mono 3.x in Ubuntu/Debian