There seems to be an issue with the Resource Bundle Editor Plugin for Eclipse.

I installed version 0.7.7 into a fresh install of the Eclipse 3.3 SDK and was unable to open a resource file. I would get the following error:

Can’t start the AWT because Java was started on the first thread. Make sure StartOnFirstThread is not specified in your application’s Info.plist or on the command line

To fix it I edited the eclipse.ini file (/Applications/eclipse/Eclipse.app/Contents/MacOS/eclipse.ini by default) to add the following line:

-Djava.awt.headless=true

Once I did that it was fine and I was able to edit the resource bundles.

Hope this helps someone searching for the issue!