Custom error pages in IIS look very great, but in case of a CMS, they seem to be too static most of the time. Here is a short explanation how you can create correct error pages with Composite C1 CMS.
Glimpse shows execution timings, server configuration, request data and more, all in browser, with no changes to your application code. Just install the NuGet package, and you're good to go!
Scenario: I had a base-class which was implementing the IDisposable pattern (including the GC.SuppressFinalize() part). From this class, I inherited a sub-class which also required doing some disposing stuff.