The best solution is to update to QuarkXPress 7.5 or upgrade to QuarkXPress 8. If this is not an option for you, launch QuarkXPress in Rosetta mode. To do this:




  1. Select the QuarkXPress application icon in the Finder and press Command I.

  2. Click on the checkbox “Open with Rosetta.'

  3. Launch QuarkXPress.



If this solution does not work, then follow the steps given below:




  1. Navigate to the following location: Hard Drive > Applications > Font Book

  2. Select all the fonts.

  3. Go to File> Validate Fonts.

  4. If any corrupted fonts are located, remove them from the system.

  5. Launch QuarkXPress.



Background:

QuarkXPress 7.3 is not optimized to run under OS X Leopard (10.5). If a corrupt legacy QuarkXPress 7.3 Preferences file is loaded into the Preferences folder (specifically the Palette preferences), QuarkXPress tries to update them and fails. This is what is causing the screen to change colors and QuarkXPress 7.3 to crash. This problem can also occur if you have corrupted fonts loaded and active in the system.