Why do I receive an "Unable to read MAT-file" error when I load a GUI in MATLAB 7.2 (R2006a) and earlier versions?

When I try to load my graphical user interface in MATLAB 7.2 (R2006a) or previous versions, I receive the following error message:

 Error using ==> load

 Unable to read MAT-file D:\MATLAB\R2006a\work\test.fig: not a binary MAT-file.

 Try LOAD -ASCII to read as text.

 Could not create figure:

Answer 1

[MathWorks Support Team]

To allow users to save data larger than 2 GB, MATLAB 7.3 (R2006b) offers a new HDF5 format for saving MAT-files. As FIG files technically are MAT files, the files you are attempting to open may have been created using this format, which is not supported by previous versions of MATLAB.

To work around this issue, you will need to open the GUI in GUIDE in MATLAB 7.3 (R2006b) or higher and resave with the MAT-file preferences changed to MATLAB version 7 or later. You can set this in the menu

 File -> Preferences -> General -> MAT-Files.