Webpage Not Rendering, displays source code instead in all browsers

If I create a empty project with a "hello world" tag (Bootstrap project with ServiceStack), it displays the sourcecode instead of redering the page. If I delete the project and start from scratch again, the same thing happens.

I know while I was trying to trouble shoot a 404 error, I bumped into something that allowed me to check a value to show the code instead of rendering the page, but I don't remember where it is to turn it off. Because this happens across projects, I'm assuming this is a setting in Visual Studio, I just don't remember what it is.

Any assistance is greatly appreciated.