Can't create a Dynamic Web App in eclipse

I am working in eclipse. I create a new Dynamic Web Application and it gives me this error:

One or more constraints have not been satisfied.

> Cannot install project facet Java 16. Some version of this project facet is already installed.

I did some googling and found this:

"Cannot install project facet" error while creating a project?

So I went into the .settings folder and deleted the file but it still isn't working. What do I do? I want to create a servlet, but eclipse doesn't recogonize this as a project since I can't choose it as an option under select project.