Resource is out of sync with the file system
Eclipse produces this message when a file in an Eclipse project is changed outside of Eclipse. To avoid it:
- a) Don’t change files outside of Eclipse
- b) Refresh the workspace/project after changing files outside of Eclipse F5 or
- c) Enable
Window > Preferences > General > Workspace > Refresh Automatically
Note: in STS 2.8.1, it is “Refresh on Access”