Skip to content
logo Knowledgebase

Exception in dotnetdll page : class not registered / Windows Security Update / Known Issue

Created on  | Last modified on 


We are aware of the Sage 200 functionality issues surrounding the Financials tab, Quotes & Orders following a Windows Security Update on July 12th.

  • ERROR: Exception in dotnetdll page : class not registered, classid: {b7aa3de9-a3bf-3c02-899c-59a6943a740f}


Microsoft have since released an updated Windows Security Update which resolves this issue however, if you are still experiencing the same behaviour make sure the below settings are correct as per the D&I guide:

  • Within IIS, set Anonymous Authentication to use Application Pool Identity and set the CRM app pool user to be the S200Services user as per the D&I guide.
  • After making this change, make sure all users are logged out of CRM and 200 then reset IIS.