I go to Settings - Ruby SDK and Gems, and pick out C:\RailsInstaller\Ruby1.9.3\bin\ruby.exe.
It loads up a bunch of gems on the right side, and looks like it's going to work.
I hit OK, and still have awful syntax highlighting and it still thinks it has no Ruby interpreter.
I've tried invalidating the cache, and even downloading a new version of ruby and pointing it to the new binary ruby.exe file.
I faced this problem when I moved my project to another PC running a different version of JRuby. resolution:
- close RubyMine
- delete
.idea/folder - re-open project in RubyMine
I had this problem when git somehow got confused about whether files in RubyMine's .idea directory were in git or not. Doing things like git stash would clobber my RubyMine configuration. I fixed it by recloning my repo, copying .idea from the old clone to the new, and fixing my RubyMine configuration. After that it stayed fixed.
No idea whether that's why you're having this problem, but I'd look in to whether RubyMine is having any trouble writing files to .idea, or whether anything is changing those files behind RubyMine's back.
Highly suggest if you're going to check in the .idea folder (I would ignore it personally) try using this gitignore to configure it correctly: https://github.com/github/gitignore/blob/master/Global/JetBrains.gitignore
来源：https://stackoverflow.com/questions/24454272/rubymine-no-ruby-interpreter-configured-for-the-project