Things I would try in order:
- Start eclipse with -clean flag:
./eclipse -clean
- Delete the .lock file:
workspace/.metadata/.lock
- Inspect the log files:
workspace/.metadata/.log
- Delete the .snap file
workspace/.metadata/.plugins/org.eclipse.core.resources/.snap
- If you are using eclipse4, delete workbench file:
workspace/.metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi
- Delete the project .markers.snap files
workspace/.metadata/.plugins/org.eclipse.core.resources/.projects/*/.markers.snap
Edit: .snap file can be named .snap or .markers.snap depending on your eclipse version