when I change a properties file's content, Eclipse always show error,say "Description Resource Path Location Type The project was not built due to "Could not delete '/lichong-test-tester/target/test-classes/config'.". Fix the problem, then try refreshing this project and building it since it may be inconsistent lichong-test-tester Unknown Java Problem ". I have to clean and rebuild whole project to solve this problem ,can anybody tell me how to avoid this. https://skydrive.live.com/redir.aspx?cid=02a1e6543b4cc73e&resid=2A1E6543B4CC73E!458&parid=root that's my Screenshot