500.19 error in IIS7 when an error occurs?

I've been dealing with this issue for the last few days and found the solution. A Web. Config file is likely specifying an absolute path for one of the error pages.

This may not be the Web. Config of the application you are testing. For me, it was the website's Web.

Config file.

I had the same problem when I installed Active Directory Certificate Services on the domain controller. Both of them were using port 443. I change the one for certificate services to the server IP Address and left the exchange server unassigned.

That solved my problem.