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Did DisplayPad crash my Mac OS X Lion upgrade?

Well, those were a good few hours of my life that I'm not going to get back!

Like, I suspect, many others, I downloaded Apple's OS X 10.7 Lion upgrade for my MacBook Pro from the App Store yesterday. To hell with my download allowance, I thought; I'll just not watch YouTube for the rest of the month.

The installation went smoothly enough. It did, however, identify one piece of incompatible software, DisplayPad, which it dutifully moved to the Incompatible Software folder at the root of my hard disk.

A quick search on my Search Engine of Choice revealed an updated version of DisplayPad, 1.0.2, which claims to be compatible with Lion. So I downloaded this latest version and installed it. Given the nature of DisplayPad, I expected it to install some kind of display driver or OS extension to allow the UI that would be tagetted at a second monitor to be relayed to the iPad. This, the installer did and on succesful completion told me that a restart was required.

I restarted the machine.

At the initial Apple Logo screen, the progress spinner sat for a while before moving on. The next screen that I saw was the 'fabric-look' background to the Lion logon screen. And this is where it all went wrong. Despite waiting for many minutes, the login icons never appeared (I should make it clear at this point that I've disabled automatic login for security reasons). My MacBook Pro had crashed!

After a while, I powered off the machine, restarted and confirmed that the behaviour remained.

I powered off again and this time, restarted into Safe Mode by holding the Shift key down. I was able to login successfully and did a bit of poking around, but couldn't see anything obvious. I also wasn't sure how to uninstall DisplayPad. Dragging it to the Trash Bin doesn't seem sufficient; no surprise, given that it's installing that display driver. Again, my Search Engine of Choice yielded no suggestions and the FAQ on the Clean Cut Code site (the producers of DisplayPad) contained only two, less that useful, questions and answers.

After an hour or so of trying, I gave up and this time restarted using Command-R to bring up the recovery tools.

Fortunately, my MacBook Pro is regularly backed up to an external hard disk that is attached to my Airport Extreme (my current Wireless Access Point of choice) using Time Machine. The Recovery Tools give you the option of restoring from a Time Machine backup and so I selected the last Snow Leopard backup taken shortly before I upgraded to Lion.

What followed was a restore lasting around 13 hours. I should consider myself lucky; the original estimate was 21 hours!

Once the restore was complete, I rebooted and started again. Microsoft Office wanted to rebuild its internal identity store (it warned me that this usually happens when you restore from Time Machine). I was also disappointed to find that Fingerprint, software to support AirPrint with non-AirPrint compatible printers, had reverted to Trial mode and I can't find my license key. That's a separate issue, though, and not of concern here.

So guess what I did? I let DisplayPad update again. Like a fool!

When I rebooted, I had exactly the same symptoms. The machine got as far as the login screen, but displayed no icons, no prompts, nothing.

However, in my frustration, I must admit to having a bit of a rattle on the keyboard. Not a vigorous one, obviously, as this is a MacBook Pro and warrants some respect. I was surprised to hear one of those "Don't press that key again" kind of sounds.

So, I hit the Enter key and to my further surprise, was logged in to the Guest account (which has no password).

I logged out and was greeted, again, with a login screen with no icons, no prompts, nothing.

This time, I pressed the first letter of my username, Enter, my password, Enter. To my relief, I was logged in to my account! Hooray!

So, it would appear that DisplayPad's graphics driver is screwing up the Login screen. I could be wrong, but that's my belief at the moment. I've worked around the problem temporarily by turning on Auto-Login again, so the Login screen is never required. And I've e-mailed Clean Cut Code for some advice; if not to solve the problem then how to successfully and completely uninstall the application.

I appreciate that these things happen, but I spent a lot of frustrated hours just getting my machine back to a usable state again. While I await a proper resolution, I'm going back to tame this Lion again...


Well, I'm pretty convinced that it's a DisplayPad problem, that's for sure!

While mooching around Lion some more, I was finding all kinds of problems. Firefox 5.0.1 wouldn't display any content in its windows unless I start in Safe Mode. Google Earth didn't show me the Earth, that sort of thing.

So, a bit more investigation, and I think I've managed to work out how to uninstall DisplayPad.


    (HDD Root) /System/Library/Extensions

There are two files:



Move these to the Trash to delete them.

From the


folder, delete DisplayPad.app by moving it to the Trash bin, too.

On restart, things seem to be back to normal. Specifically, Firefox is now working without resorting to Safe Mode and Google Earth is going its stuff, too.

And, YAY! The icons are back in the Logon screen!

Looks like DisplayPad needs a bit more work before it's ready for Lion.

Further Update:

I heard back from Clean Cut Code about the problem. Apparently, it's due to a bug in Lion that affects machines with NVidia 9400M graphics cards. My machine is a mid-2009 MacBook Pro and has dual-graphics, an NVidia 9400M for low-power use (typically on battery) and an NVidia 9600M GT which offers higher performance and is generally preferred when connected to the mains. Expect an update from Apple or Clean Cut Code sometime soon that resolves the issue.

They also advised removing


if it exists. It didn't exist on my machine, but could do on yours.

Posted Jul 21 2011, 04:12 PM by Steve Morgan
Filed under: , , , , , , ,


JBradford wrote re: Did DisplayPad crash my Mac OS X Lion upgrade?
on Sat, Jul 30 2011 2:31

Thanks for this article, Steve. I experienced this exact problem this morning. I deleted the files for DisplayPad you indicated and no more login problems.  

As an interim solution, just to be able to login, booted up  in safe mode (startup holding shift key) and then changed my login options to allow auto login.  I was able to boot into my account without the restrictions of safe mode after enabling auto login.  After deleting the DisplyPad files and I was sure everything was working, I went back in and disabled auto-login.  The login screen showed up just like it should from there on out.

BTW, there was no /System/Library/Extensions/SSFrameBuffer.kext on my system either.  

Good to be on the other side of that one.  Thanks again.

Big Knee wrote re: Did DisplayPad crash my Mac OS X Lion upgrade?
on Fri, Aug 5 2011 15:20

Had the exact same problem with the exact same computer, graphics card, and Lion.  Removing the two kernel extensions resolved the issue.  

Thank you, thank you, thank you!

Matt wrote re: Did DisplayPad crash my Mac OS X Lion upgrade?
on Sun, Aug 7 2011 21:01

Thanks, I did a search for "Lion Crash Logged Out" and your post about displaypad was first up, I had forgotten I even had it installed. This issue cost me hours of work and was happening randomly every couple hours. Thanks for sharing this out.

Lydia wrote re: Did DisplayPad crash my Mac OS X Lion upgrade?
on Sat, Aug 13 2011 22:21

Thank you! Thank you! Thank you!

I had worked out DisplayPad as the culprit pretty early. Also the logging in without seeing anything. But I didn't know how to uninstall it.

Thank you, again!

Dan wrote re: Did DisplayPad crash my Mac OS X Lion upgrade?
on Fri, Sep 2 2011 23:57

This worked great for me and just saved me from having to revert.  Thanks!

Steve Morgan 2008. All rights reserved.
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