Unable to debug some aspx pages in ASP application

Question

I have a classic ASP website running on IIS. I opened it with VS 2015 (Open website in File menu) and saved the solution (when opening it it said this is a precompiled website - whatever that means). Then I attached to process to debug it.

Now, the breakpoints I placed are hit on some of the .aspx pages, and not on others. Any idea why this might be the case? I checked the webconfig and it has debug option set to true. Probably some PDB files are missing. People suggest to rebuild the website, but when I click build or rebuild solution, the process completes immediately with success, so I doubt anything was recompiled at all.

I can modify the code of those pages and the IIS recompiles them on the next request, but not sure why the breakpoints don't get hit there. They obviously are once I put something like Debugger.Launch() in my code, but it's not what I want.

I'm no expert so I'd be grateful if you could help me out with this.

Answer 1

Precompiled website means it improves performance on some ASP.NET websites. It can be used to optimize static sites. We explore strategies for other types of sites. This speeds up the first access to pages in your site. And if you want the faster option for the site once deployed, please consider "site precompilation." Let's assume your site is high-volume, popular and important. It is important that the site respond instantly when a customer visits.

Hope this is helpful.