Hi. I have a Mac running OS X version10.7.5. I have Photoshop Elements 8 and 9 installed. They work fine. I also have Photoshop CS5.1 installed. It worked fine for a number of months until yesterday. Now, it will not open. I re-installed from the disk, and went throught the whole process, and it said "Done". However when I double-click the icon I get the spinning color wheel for a second or two, and the icon blinks, but nothing opens. I restarted my machine, but that didn't solve anything - I got the same result. I sure would appreciate any help you can provide. Thanks.
Are Photoshop and OS fully updated?
As with all unexplainable Photoshop-problems you might try trashing the prefs (after making sure all customized presets like Actions, Patterns, Brushes etc. have been saved and making a note of the Preferences you’ve changed) by keeping command-alt-shift pressed on starting the program or starting from a new user-account.
System Maintenance (repairing permissions, purging PRAM, running cron-scripts, cleaning caches, etc.) might also be beneficial, Onyx has been recommended for such tasks.
Weeding out bad fonts never seems to be a bad idea, either. (Validate your fonts in Font Book and remove the bad ones.)
If 3rd party plug-ins are installed try disabling them to verify if one of those may be responsible for the problem.