Sometimes it becomes necessary to perform debugging of client-side code. This would usually be needed in the following circumstances:

  • Allowing us to see how a Formula that is set to execute on a form [e.g. onChange() event] interacts between the web page and the server
  • Debugging some element related to the North52 user interface


In order to perform this debugging we need a free debugging tool called Fiddler. If you do not have this installed please download from

Fiddler Screenshot - North52 Business Rules Engine for Microsoft Dynamics 365

Setup Debugging

  • In order to perform debugging you need to start Fiddler
  • It should look something like the screenshot above
  • If the CRM system you are accessing runs under HTTPS \ SSL then go to Tools > Fiddler Options and enable the 2 check boxes as shown in the screenshot below. Note some popups will appear and you can just accept these.
  • Ensure that in the top left hand corner of  Fiddler that the Capture Traffic is turned on

Decrypt HTTPS Traffic


Capture Traffic


How to Perform Debugging

  • Now that Fiddler is up and running you need to navigate to the web page in CRM and perform the desired action
  • This could be changing the value of a field on the form which would then trigger the North52 Formula to execute
  • What happens then is Fiddler records this interaction so we can see all the details of what happened
  • You can click File -> Save -> All Sessions to save a file which will contain this interaction
  • Finally you can send this file to to get it reviewed and a resolution to your issue