I'm working now on Sublime Text 3 as text editor for LaTeX, and I'm using LaTeXTools. So far so good. However, I've just created a new file [Ctr+N], I've checked that the syntax is written in LaTeX View/Syntax/LaTeX/LaTeX. I've also checked the builder system Tools/Build System /Latex. However, when try to compile Ctr+B it says "is not a TeX source file: cannot compile".
Any ideas why is this happening?