title: Critical Problem with Sharepoint Timer Job Properties
body: <p>Some minutes ago I tried to create a time job</p>
  
  <p>A added some properties like </p>
  
  <p>this.Properties.Add("fileName", fileName);
  this.Properties.Add("username", new NetworkCredential("username", "passworD");</p>
  
  <p>After updating the job a get a critical error in the Timer Job list of the Central Administration occured.</p>
  
  <p><em>The platform does not know how to deserialize an object of type System.Net.NetworkCredential. The platform can deserialize primitive types such as strings, integers, and GUIDs; other SPPersistedObjects or SPAutoserializingObjects; or collections of any of the above. Consider redesigning your objects to store values in one of these supported formats, or contact your software vendor for support.</em></p>
  
  <p>Now Im unabled to delete or retract the job with SPJobdefinition's Delete() method or other classes within the SPObject model.</p>