Originally Posted by jeaton2012

I seem to have permanently fixed the applications not opening problem:

1) Wait for xpchelper to crash
2) Open terminal and type these in:
"sudo su"
"cd /private/var/folders"
"find /private/var/folders/ -type f | grep -i com.apple.xpchelper.cache"
3) cd to the first one that shows up on the list (it will be in a separate folder from the other xpchelper caches)
"rm -r com.apple.xpchelper.cache"
"pico com.apple.xpchelper.cache" ---> hit ctrl+o to save and ctrl+x to exit
"chmod -x com.apple.xpchelper.cache"
4) Reboot and you're done!