Q: OSX Lion + 2011 iMac 27'' + Video = Freeze

iMac mid 2011 i7 3.4ghz, 1To,Ati 6970, 12Go DDR3

OS X Lion.

I use safari/firefox/chrome.

Flash 10.3.181.34

The video start and the imac freeze immediatly, the mouse works but the mac doesn't respond.

The problem is with Flash. Adobe has admitted they're having a difficult time with Flash on Lion which is really odd considering they had months and months to tweek it. Here is a link to their offical press statement.

http://kb2.adobe.com/cps/905/cpsid_90508.html

and another article with more up-to-date information.

http://www.macrumors.com/2011/07/22/adobe-retracts-claim-suggesting-lion-may-lac k-support-for-flash-hardware-acceleration/

I am running a 2011 iMac i7 3.4 2GB 6970 12 GB DDR3, SSD + 1TB HDD, and just upgraded to Lion yesterday from 10.6.8 which is when I first noticed this issue for myself. 

I'm not convinced this is a Flash issue because for me the freezing occurs on playing videos in iPhoto and iTunes.  The sound continues to play and the mouse is available but everything else is completely frozen.  A hard reboot is the only way to recover.

I also notice that everything is fine after reboot and I am only able to reproduce the freezing after resuming from sleep and then playing a video.

I have also done a full hardware test (no issues), full permissions repair and hdd repair.

Having this exact same problem with my 2011 27" iMac. Sometimes when I simply just open up youtube my system will completely freeze up, but I am still able to move the mouse cursor and whatever music I have playing in iTunes carries on. I've had to hard reset my system so many times.

Ditto.  Same everything; cursor moves but that is it.  All I can do is hit the on/off button and that doesn't even seem to be very quick in responding.  Just got this beautiful machine-- hope it's not a major issue.

Two weeks young iMac 27". Lion installed day before yesterday.

2.7 GHz Intel Core i5; 4 GB 1333 MHz DDR3 

One more to the list.  This is certainly not a flash problem.  I have uninstalled flash and it still happens with apple HD trailers.  It happens most often when I hvae slept the computer and awoken it to play a video of some sort.

I'm having the same issue. Second time it's happened so far. I've only noticed it while trying to play flash videos in Chrome though.

Same iMac 27" 2011.

I have it and it is not a flash problem.  It freezes with H.264's, flash and quicktime (like Apple's trailers site).  It happens to me after my computer is closed and opened again (Macbook Pro) and I have to reboot.  After it does freeze in Safari when it tries to start playing a video, it actually kills the whole sound card.  You can't hear any video after a freeze in VLC or Quicktime.

It's a bug that is bad enough (plus a couple other problems) that I'm going back to Snow Leopard as I type this.

I can confirm that this only happens when the computer is woken from sleep. It always works after I have hard reset.

I am having the exact same issue. It happened when I tried to search Youtube. A video was playing on the Youtube site when I was try to search it. The screen is frozen but I can move the mouse. The only way I can get out of it is by a hard boot. Any ideas? The version of Flash I am running is: 10,3,181,34

OK... so I'm not the only one. So this is obviously a massive bug with Lion...One thing: Have you all installed or updated Java yet? That seemed to help me out. rkaufmann gave me that suggestion on Wednesday.

Also, running updates I think it was last night, I was prompted to update iTunes. Have you all done this also?

Just throwing out ideas.

I have the same problem. New 27" mac ATI 6770M. Clearly not flash related but any video can trigger the freezeups. System log shows GPU debug dumps.

Ok, I just put my iMac 21.5 (2011) to sleep on purpose and logged back in to try go on to Youtube, and then it suddenly froze just like the other times. So we can conclude it only happens after 'sleep mode.' I hope Apple fixes this ASAP.

My iMac never sleeps, yet I have the exact problem descrived eariier. Playing video however right after restarting the computer is never a problem.

I have never been on this forum before and I don't know what your background is but your advice is lousy and troubleshooting skills seem to be non-existant. The posters have stated they have a i7 27" iMac running Lion and you keep asking what version they are running. You have blamed the users for incorrectly installing the update, Flash for ??? (being Adobe?) and telling them not to force a shut down, just let the computer go to sleep. It is FROZEN. The only function anyone has mentioned is that the cursor moves. Force quit doesn't work, Auto Restart doesn't work, the Dashboard isn't accessible and neither is Activity Monitor.

I guess we can just let our computer go to sleep but then what? It is still frozen, oh well I guess I should have bookmarked those sites. Oh wait, I can't go to them because it is still FROZEN.

I suspect that we will have this bug until Apple releases an update but I am no expert on these matters.

Disk Utility and DiskWarrior have found no problems. Restarting repeatedly has had no results and neither has unplugging all the accessories.