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After you upgrade to Mac OS X Mavericks (Mac OS 10.9), Illustrator crashes when you attempt to launch it.
In the Finder, browse to the folder that contains Illustrator plug-ins.
Move all third-party plug-ins to a different folder.
(Important) Press and hold Command + Option + Shift, launch Illustrator, and keep the keys pressed until Illustrator launches. This step clears all Illustrator preferences.
It's necessary to press the keyboard combination (Command + Option + Shift) in the same order as mentioned above.
(Optional) If you require your third-party plug-ins when you use Illustrator, try adding one plug-in at a time. Each time you add a plug-in, ensure that you follow step 3 to start Illustrator.
Third-party plug-ins that are not compatible with Mavericks can cause Illustrator to crash at launch.
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