This problem occurs when MATLAB is unable to detect the correct version of X11 on your MAC OS X machine. A common symptom after installation is the MATLAB icon will bounce in the Dock but MATLAB fails to launch. You might also be missing X11 entirely if it is not in Applications under Utilties. To resolve this issue, you will need to install the required version of X11.
Mac OS X 10.5 Leopard and 10.6 Snow Leopard comes with X11 installed by default. If you're upgrading to one of these operating systems or you need to reinstall X11, use the Install DVD for that specific version of OS X. The package is on the DVD, but the System folder (where the package is located) is hidden. To get to the System folder, open the DVD in Finder, then select "Go To Folder..." from the Go menu and enter the path below to find the X11user.pkg package:
System/Installation/Packages
As an alternative, to install X11 on Leopard or Snow Leopard through the GUI:
1. Insert your Mac OS X install disc. (If you have two discs it will be the "Install Disc 1")
2. In the window that pops up double click on "Optional Installs" (You may need to scroll down)
3. In the new window that pops up double click on "Optional Installs.mpkg"
4. In the installation window click Continue.
5. Read through the License Agreement and choose Continue if you agree.
6. Click the triangle next to "Applications" in order to expand the directory.
7. Put a check in "X11".
8. Click Continue.
9. Click Install.
10. Wait for the installation to complete and then click Close when it is complete.
To install X11 for OS X 10.4 (Tiger) you will need the Tiger Installation DVD. There is no download available from Apple's website to install X11 for Tiger. This package is available as an optional installation on the Tiger Installation DVD. The package is called X11user.pkg and can be found on the DVD in the /System/Installation/Packages folder. Once installed, MATLAB should start as normal.
NOTE: Please be sure to use the correct Tiger DVD in order to install X11 for your machine's processor type. If you are running an Intel Mac, use the Tiger DVD for your Intel architecture (grey disk). If you are running a PowerPC Mac (PPC), use the Tiger DVD for your PowerPC architecture (black disk).
If you receiving this error and you are using OS X 10.3 (Panther), you can obtain X11 from downloads here:
Again, this download is only available for OS X 10.3 (Panther) and it will not install X11 for Tiger or Leopard.
NOTE: X11 is required for MATLAB versions R2010a and older. R2010b and R2011a still rely on X11 for some functionality (such as using SIMULINK) even though MATLAB may install and start without X11.
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