While it is a good practice to try to get to the root of things, if you are in the middle of something you might just want to turn the machine off and on again. For instance, I randomly got this error earlier
The type or namespace name 'Practices' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?)
I didn't know I had changed anything so I tried to look for a solution. It seemed like I had all the references in place. So I scoured the Internet looking for information. I couldn't find anything terribly relevant as this wasn't a new project; I'd been working on it for a while now. So, I tried something simple. I turned the computer off. Then, I turned it on and the error is gone. I would still like to know what happened and why Visual Studio was giving errors for no apparent reason though.