Since upgrading to Lion, I cannot access any of the local functions in the CUPS web-based interface. The response I get is "Internal Server Error".

For example:

http://localhost:631/admin or http://localhost:631/jobs/

The printers are all working fine, but I can't access job queues, etc.

Any ideas?

2 Answers 2


Enter the following at a Terminal command prompt:

cupsctl WebInterface=Yes

You will be able to access the CUPS web interface thereafter.


I have this problem too on all Lion machines. Somehow Apple did not set up the cups system correctly. In /var/log/system.log you will find error messages like "xpchelper[6719]: Could not get real path of user account (uid: 26) home directory: /var/spool/cups; error: The operation couldn’t be completed. Permission denied. Using home directory." uid 26 is user _lp.

It helps to become root ("sudo bash") and kill the running cupsd ("killall cupsd") and restart it ("cupsd"). Afterwards cups admin works in the browser.

I know that this is a temporary fix only which will be gone with the next reboot.

If you want to do this without using Terminal, you can open AppleScript Editor, and create an AppleSript with the following content:

 do shell script "/usr/bin/killall cupsd; /usr/sbin/cupsd" with administrator privileges

Save the AppleScript as an Application. When you double-click the application, it will prompt you for your password (using a standard MacOS X dialog box), then restart the print daemon. If you find yourself having to do this often, having an icon to double-click to do it can make the job easier and less intimidating (and no Terminal needed!).

  • Can you explain how to do the above so that a non-computer savvy person could "ecome root ("sudo bash") and kill the running cupsd ("killall cupsd") and restart it ("cupsd")"? I have an older model Samsung printer that wouldn't work when I upgraded to Lion. However, I found some advice on a blog that helped me hook up my printer using CUPS, but since the last upgrade of Lion I get "Internal Server Error" and can't resolve any printing issues. My printer is now only occasionally working and I can't fix it. Any advice would be helpful. Thank you! Jennifer
    – user19000
    Commented Feb 20, 2012 at 17:44
  • Open a terminal window. Enter the command "sudo bash". This will ask for a password. Enter your login password. Enter the command "killall cupsd". Finally enter the command "cupsd". Close the terminal window. Commented Feb 20, 2012 at 22:28

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .