Mac OS X 10.3, 10.4: Some applications only work in one account at a time

Some applications are designed to work with one user account at a time. If such an application is already open for one user, and you switch to a different account (for example, with Fast User Switching) you can't open the same application again.

When you try to open an application that is already open in a first user account, nothing happens if you click the application's icon in the Dock. If you open the application by double-clicking its icon in the Finder, a message containing "error -1026" may appear.

As a workaround, quit the application in the first account before opening it in a second account.

Contact the application's publisher for more information or further assistance. Because some applications are designed to be used by one account at a time, this may be considered normal behavior by the application's publisher.

Examples of Apple applications that you can't open by more than one user account at a time

• Final Cut Pro
  
• Final Cut Express
  
• DVD Studio Pro
  
• LiveType
  
• Cinema Tools
  
• Compressor
  
• Shake
  
• Soundtrack (Mac OS X 10.3 only)
  
• Logic Audio
  
• iDVD
  
• iTunes (Mac OS X 10.3 only)
  
• Backup 2.0 or earlier (.Mac)

• iTunes (Mac OS X 10.4 or later)
• Soundtrack (Mac OS X 10.4 or later)
• iPhoto
  
• iMovie
  Note: iMovie can't control an attached camera if the camera is already in use by iMovie or another application in a different user account.
  
• iSync
  
• iCal
  
• Keynote
  
• AppleWorks
  
• Safari
  
• iChat
  
  Note: iChat logs out the currently signed-in ID before switching to the other user because you can't have two different iChat accounts signed in at the same time from the same computer.