title: How to solve Sharepoint CSOM HTTP Request Error 429?
body: <p>The sharepoint often displays error 429 (Too many requests) and we have already taken all the actions described in the article below, but some requests continue to be blocked.</p>
  
  <p><a href="https://docs.microsoft.com/en-us/sharepoint/dev/general-development/how-to-avoid-getting-throttled-or-blocked-in-sharepoint-online" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/sharepoint/dev/general-development/how-to-avoid-getting-throttled-or-blocked-in-sharepoint-online</a></p>
  
  <p>Our scenario involves a customized desktop application (add-in) for Word, Excel, Power Point and Outlook that accesses the Sharepoint through CSOM (with user's network credentials) and we already registered this Add-in through the "/_layouts/15/AppRegNew.aspx" page and decorated all of our requests with "NONISV|{OUR ORGANIZATION NAME}|{OUR ADDIN NAME}/1.0 ", as described in:</p>
  
  <p><a href="https://docs.microsoft.com/en-us/sharepoint/dev/sp-add-ins/register-sharepoint-add-ins" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/sharepoint/dev/sp-add-ins/register-sharepoint-add-ins</a></p>