title: System.Security.SecurityException: Request for principal permission failed
body: <p>Can anyone help point me in the right direction of how I might be able to fix this error?</p>
  
  <pre><code>System.Web.Services.Protocols.SoapException: Server was unable to process request. 
       ---&gt; System.Security.SecurityException: Request for principal permission failed.
  at System.Security.Permissions.PrincipalPermission.ThrowSecurityException()
  at System.Security.Permissions.PrincipalPermission.Demand()
  at System.Security.PermissionSet.DemandNonCAS()
  at LiveDocx.MailMerge.SetLocalTemplate(String template, String format)
  </code></pre>
  
  <p>I have installed this software that my company purchased from LiveDocx. So, I don't have ability to modify code or even read the code. I have installed everything according to their documentation and the site is confirmed to work. I can only change settings in IIS, folder permissions, and Web.config. Our server, their software.</p>
  
  <p>Now, I am having issue with staying logged into the webservice. Before you think it is the soap client, I have confirmed that it works by calling the vendor's servers. </p>
  
  <p>Locally, I can successfully call the web service during login and it works fine. However, when I make a subsequent call, I get the <code>Request for principal permission failed</code>.</p>
  
  <p>At the request of their technical support, I have added <code>&lt;trust level="Full" /&gt;</code> to the web.config, but that didn't work. Now, they have stopped replying to our emails. </p>
  
  <p>I am not an ASP.NET developer, so my knowledge is limited on server settings. Can someone point me in the right direction why this error happens and a few places to look to resolve this issue?</p>