I have recently returned to a project after not using it for a couple of weeks. The project was not created in Eclipse it was imported, and there is no \'.classpath\' file in t
I had a similar problem after changing my project to Gradle. When I right-clicked on javaw.exe->Properties in the 'debug' view, I saw the classpath was (mostly) missing, for instance the 'bin' directory containing the classes wasn't there.
Solution for me was just to delete the 'run debug configuration' and create a new one. After that the classpath was included and I could run it from Eclipse again.
Hope this helps someone out there.