UPDATE: I was able to restore Photoshop to normal operation by reinstalling the Photoshop CS5 application.
Since I installed FontExplorer X Pro shortly before discovering this Photoshop problem, I suspect FontExplorer's Photoshop plugin as the possible cause of the problem. I would appreciate hearing from anyone who is successfully using FontExplorer X Pro with the Photoshop CS5 plugin installed.
I am now getting the same errors on one of my computers, I am running an imac which is giving me that error but on my macbook pro i am not getting it. I have the exact same software on each of them. I cant figure out why it is fine on the macbook pro but wont work on the imac. I am running suitcase fusion 3 on both computers. Any help would be appreciated.
Since you're having the same problem with a different font manager installed, it looks like the problem may lie with Photoshop rather than the font management software. I'm going to file a bug report with Adobe.
Meanwhile, you might want to uninstall Photoshop CS5 (Utilities/Adobe Installers/Adobe Creative Suite 5 Design Premium) and reinstall it from the original disc. You do not need to deactivate anything before doing this.
I just did a bit of playing around, I managed to get it to work but i had to turn all my fonts in suitcase fusion 3. The problem might actually be the font managers plug ins, right now the only fonts i am using in it are the system fonts. I'm going to explore more when i get a chance but at least its a quick fix for anyone with the same issue.