Open your .project file, and replace the
<natures>
<nature>org.radrails.rails.ui.railsnature</nature>
</natures>
Here’s how my project looks like
<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
<name>typo</name>
<comment></comment>
<projects>
</projects>
<buildSpec>
</buildSpec>
<natures>
<nature>org.radrails.rails.ui.railsnature</nature>
</natures>
</projectDescription>
Then either refresh your project or restart eclipse/RadRails. The Project icons should now have the little decorator with the Rails logo.
Thank you. I didn’t have to recreate my project with this trick