title: Sometimes - cannot build Windows Azure Cloud Service - Object reference not set to an instance of an object?
body: <p>I've got a solution where I've got worker role, some project library and cloud service. Sometimes I cannot build solution (without changing source code or anything).</p>
  
  <p>Output windows shows:</p>
  
  <p>1>Error: Object reference not set to an instance of an object.
  ========== Build: 0 succeeded, 1 failed, 2 up-to-date, 0 skipped ==========</p>
  
  <p>When I try edit worker role properties in Cloud Service project, I got popup window "Object reference not set to an instance of an object".</p>
  
  <p>When I try to remove worker from Cloud Service project, I got popup window</p>
  
  <p>"Windows Azure Tools for Microsoft Visual Studio.</p>
  
  <p>The service definition or the service configuration is invalid. Please fix the error(s) in the service definition (.csdef) or service configuration (.cscfg) files to perform this action."</p>
  
  <p>I'm not sure if it is connected with build problem - but when build is working those problems also not exist, so I can assume that this is somehow connected. </p>
  
  <p>This is strange because I can't figure why sometimes it's working and sometimes not. </p>
  
  <p>Anybody?</p>