R file is missing android

Question

i was using Eclipse Helios but due to performance issues i changed to Eclipse Galileo and installed the ADT plugging, and added my sdk folder to Elcipse Preferences. Now R.java disappeared from all of my projects. How can i fix this, i did Project/Clean but that won't generate the files, there's nothing wrong in my xml and there's no out.xml in any of my projects.

Thanks in advance

Answer 1

In my experience there is a mistake in the xml somewhere. Eclipse will no doubt tell you where. After I fix the error R appears.