If you are seeing this error what I would recommend is to add the JDK jars to your eclipse “Installed JRE”. This will then use the JDK for developing Grails rather then using the standard JRE.
To change to using the JDK in Eclipse
- Go to Window -> Preferences.
- Select Java -> Installed JREs
- Click “Add” button
- Go through the wizard to add your downloaded JDK
- Select your newly added JDK back at the main window
Then you should be good to go!