Problems running Logic 9 in Lion... SOLVED!!
I don't believe it, but I actually found the solution. After trying unsuccessfully to launch, uninstall, reinstall, and troubleshoot Logic Pro on my new (pre-owned) Macbook Pro, I kept hitting a brick wall. The Logic Pro splash window would pop up, stay there for about 3 or 4 minutes, then just inexplicably crash. Then I realized that the splash window was actually an error message with invisible text. I did a 'Select All' and copied the text to TextEdit, only to discover the following message:
• Logic Pro requires that your system have ProKit 5 installed; this system has ProKit 0 installed.
Of course, I did a search of the Apple Support page, downloaded and installed ProKit 5.0 here (http://support.apple.com/kb/DL863) and voila! Should work for you too, I imagine... especially considering how much searching I did, only to find no solutions. Let me know if this is helpful at all. Good luck!!
Logic Studio, Mac OS X (10.7.3)