Why am I unable to open the GUI I created in MATLAB 7.0 (R14) in MATLAB 6.5.1 (R13SP1)

If I try to run a GUI (which I created or modified using MATLAB 7.0 (R14) in MATLAB 6.5.1 or earlier, I receive an error message:

 ??? Error using ==> load

 Unable to read MAT file C:\MATLAB6p5p1\work\untitled.fig

 See FILEFORMATS for a list of known file types and the functions used to read them.

 Error in ==> C:\MATLAB6p5p1\toolbox\matlab\iofun\hgload.m

 On line 45 ==> fileVars = load(filename,'-mat');

Answer 1

[MathWorks Support Team]

In MATLAB 7.0 (R14), MAT-files are saved using compression by default. Figure files are a type of MAT-file, so they are also saved with compression. In order to use figure files from MATLAB 7.0 (R14) in earlier versions of MATLAB, you can modify your preferences so they are not saved with compression. To do this, select the following:

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

   Select "Ensure backward compatibility (-v6)"

However, a separate but related issue is that the objects created in MATLAB 7.0 (R14) might not exist in MATLAB 6.5 (R13). Most of the graphics functions accept a first input of 'v6', which is utilized to create the older version of the object:

plot('v6',1:10)