In Visual Studio, I right click on the project I want to add a class to, click 'Add' -> 'Class...', and when the class gets created, instead of the class associated with the right project(https://i.stack.imgur.com/o1zMD.png), it just gets associated with 'Miscellaneous Files'(https://i.stack.imgur.com/IUsGe.png). I'm assuming this is why it doesn't recognize any of the packages I'm trying to use that it recognizes just fine for other classes(https://i.stack.imgur.com/rNLDt.png). Why is this, and how do I get Visual Studio to associate new classes with the correct project?
I tried the top 7 answers on this question: Visual Studio - project shows up as "Miscellaneous Files". I was going to try the 8th answer, but Visual Studio won't let me open my .csproj file.