How do I repair permissions and rebuild the cache in Mavericks and earlier?

[Hervé]

It's required after any kext addition, removal or modification, whether in /S/L/E or in /L/E.
 
To repair permissions, type the following Terminal commands:

sudo chmod -Rf 755 /S*/L*/E*
sudo chmod -Rf 755 /L*/E*
sudo chown -Rf 0:0 /S*/L*/E*
sudo chown -Rf 0:0 /L*/E*

`
To rebuild the cache, type the following Terminal command:

sudo touch -f /S*/L*/E*
sudo touch -f /L*/E*

The cache should then automatically rebuild itself.