Finder doesn't launch when a specific user logs in

Question

There are three user accounts on a system running Yosemite 10.10.1.

1. When a specific user logs in, Finder does not start.
2. The keyboard shortcut for Force Quit (⌘-⌥-esc) works, but Finder is not on the list.
3. The keyboard shortcut for restart (⌘-⌃-⎋) also works.
4. Finder does start when either of the other two users logs in.
5. In the affected account's ~/Library/Logs folder, I noticed SystemUIServer_2015-01-14-135204_ComputerName, including the following, which may or may not be relevant:

Crashed Thread: 2 Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x000000010db8cca0 VM Regions Near 0x10db8cca0: VM_ALLOCATE 000000010db65000-000000010db69000 [ 16K] r--/r-- SM=S/A --> VM_ALLOCATE 000000010db8d000-000000010dbd6000 [ 292K] r--/r-- SM=SHM

How is Finder normally invoked at login, and what is the best approach to troubleshoot more deeply? I realize that deleting and replacing the user account entirely would resolve the issue, but I would like to learn what is happening and how to resolve it directly.

Answer 1

First, make sure the user is the owner of their home directory. In Terminal, sudo ls -lFad /Users/(username) and that the permissions are set at least "rwx" for the owner. Likewise, for the /Users/(username)/Library/ folder.

There are temporary cache files in /var/folders/(two letters)/(more characters)/ for each user. You can find the specific one for your user by doing sudo ls -lFad /var/folders/*/* and searching for the one which is owned by the user. Moving this entire directory someplace else (like, /Users/Shared/temporary/) may allow the user to log in successfully; but, I doubt it. A cache corruption should be fixed automatically. But, in the interest of completeness, I'll list it here anyway.

There are some files in the user's Library/ folder which (if corrupted) might cause the login to hang. This list is arbitrary and not guaranteed to be complete, but it is a list of the most likely suspects. You could move these (or, even, all of the preference files) and systematically replace them to see what is causing the hangup, assuming the login works when the files are moved away.

Files in ~/Library/Preferences/

.GlobalPreferences.plist
com.apple.BezelServices.plist
com.apple.dock.plist
com.apple.dock.db
com.apple.finder.plist
com.apple.loginwindow.plist
com.apple.QuickLookDaemon.plist
com.apple.systemuiserver.plist
loginwindow.plist

Files in ~/Library/Preferences/ByHost/

.GlobalPreferences.(long string).plist
com.apple.windowserver.(long string).plist

Files in ~/Library/LaunchAgents/

(could be anything)

Files in ~/Library/LaunchDaemons/

(could be anything)

Again, this may or may not solve your trouble; but, it is a good starting point.

Answer 2

First thing I would try to do is to fix all permissions on / drive

try:
sudo diskutil repairPermissions /

and report if it helped.