I created this post to share with you one of the most common errors when setting up a SEO Site Rule for the first time in a .Net OutSystems Platform. 

 

Symptom: the user creates a Site Rule in Service Center and afterwards a 403 error is obtained every time someone tries to access the eSpace through the rule (for instance: when entering "https://www.myenvironment.com/ in the browser to access the "Directory" eSpace).

 

Cause: whenever we obtain a 403 error, the next step should be to check the IIS Logs of the server to find the sub-code of the error. These are usually located in the "C:\inetpub\logs" folder. 

As you can see in the image below, it is likely you will find that we are facing a 403.18 error:
 

If you research what this sub-code means (a quick googling will help you) you will find it translates to "Cannot execute request from that application pool.". 

 

Resolution: after looking at the Application Pools' definitions in each front-end (in the Internet Information Services Manager console) you may see that the Default Web Site is not configured for the OutSystems Applications App Pool, which is a requirement for SEO to work correctly in this scenario:
 

You can check this requirement and other instructions for correctly setting up SEO in the corresponding OutSystems Technote:

www.outsystems.com/goto/install-seo

After setting up the Default Web Site to the OutSystems Applications App Pool, the Site Rule will start working correctly.

 

Cheers!

João Proença