If CrashPlan seems to not be backing up files or repeatedly reporting zero files to back up you might try to manually clear the cache:
- Stop the CrashPlan service.
- Navigate to the cache directory for your operating system:
- Windows 10, 8.1, 7, Vista, Server 2008, And Server 2012: C:\ProgramData\CrashPlan\cache
- Windows 10, per user install: C:\Users\Username\AppData\Local\CrashPlan\cache
- Windows XP And Server 2003: C:\Documents and Settings\All Users\Application Data\CrashPlan\cache
- OS X: /Library/Caches/CrashPlan
- Linux: /usr/local/crashplan/cache
- Solaris: /opt/sfw/crashplan/cache
- Delete all files and folders found within this folder.
- Empty your computer's trash.
- Start the CrashPlan service.
OSX & Linux users
If you have to kill the service, you can just reboot after clearing the cache to restart the service, or you can search for the init file in init.d to issue a start.