I was having this problem as well - turned off System Integrity Protection (a new feature in El Capitan?) - and all is good. I can't take credit for this fix - I got the idea from the folks over at Default Folder X (who got the idea from the folks over at
Surtees Studios) in any case:
So, without further ado, here's how you turn off System Integrity Protection:
- Restart your Mac in Recovery Mode. To do this, choose Restart from the Apple menu, and as soon as the screen turns black hold down Command + R on the keyboard until the Apple logo appears on your screen.
- Select Terminal from the Utilities menu.
- In the Terminal Window that opens type:
csrutil disable
- Press the Return key.
- Choose Restart from the Apple menu.
The good folks at Surtees Studios, makers of Bartender, have a screenshots of the steps here if you want to see more details.
To turn System Integrity Protection back on, follow the procedure above but type csrutil enable in step 5.