File sharing randomly stops working

Question

Hi guys,
For some reason every once in a while the file sharing on my iMac stops working and to get it working again I need to untick and then re-tick "File Sharing"  in the "Sharing" pane in Preferences.
Any ideas?
Thanks,
Tom

Answer 1

Please take each of the following steps until the problem is resolved. Back up all data before making any changes.
Step 1
Delete all sharepoints in the File Sharing tab of the Sharing preference pane. Recreate them one at a time and test each one.
Step 2
Boot into Recovery mode, launch Disk Utility, select the startup volume, and run Repair Disk (not  Repair Permissions.) If any problems are found, repeat. Then reboot as usual.
If any sharepoints are on a different volume, repair it too.
Step 3
Boot the server in safe mode and test. Note: If FileVault is enabled on some models, or if a firmware password is set, or if the boot volume is a software RAID, you can’t do this. After testing, reboot as usual and verify that you still have the problem.
Step 4
Triple-click anywhere in the line below on this page to select it:
/Library/Preferences/com.apple.ByteRangeLocking.plist
Right-click or control-click the line and select 
Services ▹ Reveal
from the contextual menu.* A folder should open with an item selected. Move the selected item to the Trash. Repeat with this line:
/var/db/BRLM.db
*If you don't see the contextual menu item, copy the selected text to the Clipboard (command-C). In the Finder, select
Go ▹ Go to Folder...
from the menu bar, paste into the box that opens (command-V). You won't see what you pasted because a line break is included. Press return.
Step 5
Reinstall the OS. You don't need to erase the startup volume, and you won't need your backup unless something goes wrong. If your Mac was upgraded from an older version of OS X, you’ll need the Apple ID and password you used to upgrade.
If you installed the Java runtime distributed by Apple and still need it, you'll have to reinstall it.