title: Azure App Service 502 - Web server received an invalid response while acting as a gateway or proxy server
body: <p>I have simple azure service app that talks to azure storage tables . This works just fine when I run it through visual studio and gives the below error when I run it after deployment .</p>
  
  <p>Server error 
  502 - Web server received an invalid response while acting as a gateway or proxy server.
  There is a problem with the page you are looking for, and it cannot be displayed. When the Web server (while acting as a gateway or proxy) contacted the upstream content server, it received an invalid response from the content server.</p>
  
  <p>•   This use to work just fine a few months before .
  •   I have no Azure application gateway or proxy , I believe its mandatory to have one right ?
  •   The problem is there in both <a href="http://myservice.azurewebsites.net/Add/Create" rel="nofollow noreferrer">http://myservice.azurewebsites.net/Add/Create</a> and <a href="http://www.myservice.com/Add/Create" rel="nofollow noreferrer">http://www.myservice.com/Add/Create</a>
  •   There is some data base interaction that happens before the problem page comes.  I also see that that data interaction on the problem page also completes fine , as I can see from backend that the data has been added.
  •   Using application insights , I see that all the said actions returned https error 200 , none have 502 . </p>
  
  <p>I see from some web search , this is some front end error , what logs in azure will tell me the details ?</p>