title: UserProperties being shared between users in Google Apps Script published UI service
body: <p>I am working on a google apps script that is being published as a service, and accessed by multiple users via the UI.</p>
  
  <p>The problem I'm having is that when one user causes a UserProperty to be set, all the users subsequently have their UserProperty set to that also. In other words it is acting like a ScriptProperty, rather than a UserProperty, in that it is not User specific. All users appear to cause this to happen.</p>
  
  <p>I have studies my code and I just cannot see that it is anything to do with that. I make no reference to EffectiveUser, so only ActiveUser could ever be setting these values.</p>
  
  <p>My guesses are:
  - I am misunderstanding the scope of UserProperties
  - My variables have somehow become corrupted (I have had problems with other UserProperties variables doing some odd stuff)</p>
  
  <p>Has anyone experienced this, or does anyone have any suggestions?</p>
  
  <p>Regards
  Chris</p>