Tip: Handling 403 errors when setting up your SEO Site Rule

Hi everyone!
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 "http://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:
After setting up the Default Web Site to the OutSystems Applications App Pool, the Site Rule will start working correctly.
João Proença
Thank you, this solved my problem!

Awesome tip. Solved the issue we had, thanks !