Category: Technology

After upgrading an application from ASP.NET Core 2.2 to ASP.NET Core 3.0, I had some issues where controller methods in an application were returning populated objects, but the HTTP responses were blank Json documents: . To make matters worse, there were no exceptions thrown -- the application was just silently sending blank documents to the browser.

I ran into this issue earlier today after updating Visual Studio for Mac. I had tried debugging a site, and was met with the error message in Safari that it couldn't establish a secure connection with the server. Kestrel was running, and the port was correctly open -- it's just that the SSL/TLS negotiation was failing.

A @section Scripts block does not work when placed in a partial view in ASP.NET Core, which is the same functionality as in ASP.NET MVC. Unfortunately, you don't get any error messages if you try to add the section to a partial -- it just does nothing. In many cases, having a scripts section in a partial view would be an anti-pattern, since the partial can be rendered an unknown number of times. However, there are times when I believe a scripts section is warranted in a partial, particularly when you're trying to create dynamic JavaScript based on the model passed into the partial view. While you can't just use the actual @section Scripts in a partial view, you can add some HTML helper extensions to accomplish the same thing.

I'm running some ASP.NET Core applications under Kestrel on Linux proxied by NGINX. I ran into an issue recently where I was getting the following exception when I redirected with certain strings:

System.InvalidOperationException: Invalid non-ASCII or control character in header: 0x00ED

This is likely a bit esoteric, but I was setting up an ASP.NET Core 2.2 project recently where I wanted to store logs in MongoDB. I wanted to play with Serilog vs. some of the alternatives. I also wanted to use a configuration file, and I wasn't able to find any good examples online, so I figured I'd create a quick example in this post. This example is applicable to ASP.NET Core 2.2, and may work for other versions, but isn't tested with others.