Slowness in web applications might be result of a wide range of underlying issues in the application code, client side, network or web server. Therefore, system administrators should analyze IIS logs, Failed Request Tracing logs, dump files, and HTTP.SYS logs to narrow down the issue.
Development
Nuget package for System.Net.Http on .NET Framework 4.7.2 and newer versions
If your web application has dependency on the System.Net.Http Nuget package, it may break after you upgrade .NET Framework version to 4.7.2 or a newer version. This issue occurs if you are using Visual Studio 15.5 or a higher version.
Complex model binding for radio buttons in ASP.NET MVC page with Razor
Let’s say you have an ASP.NET MVC page with four radio buttons. You select one of them and click a Submit button. Form is posted. However, you don’t see the submitted values in the code. Binding between HTML inputs and Post method doesn’t seem to be working.
Web page with an iframe to a PowerApps URL keeps spinning
If a web browser starts loading the web page but it never finishes loading it, look for the resources being loaded and the debug errors in F12 Developer Tools.
If the page has an iframe, try testing the page after removing the iframe. If it works without the iframe, then look for further leads to narrow the issue down.