I created a new file, and forgot to type the extension. Then RubyMine asks how it should be displayed, so i thought: nevermind, entered the first option, and then changed the name to include the ".rb" file-extension.
Alas, unfortunately, it seems that every file which is called the same is handled as plain-text in all my rubymines.
So i have no syntax colouring, my tabs are wrong, ...
How can i revert this?