Why do MEX-files compiled in MATLAB 7.3 (R2006b) not work in previous versions of MATLAB?

I compiled a MEX-file in MATLAB 7.3 (R2006b), but the MEX-file does not run in MATLAB 7.2 (R2006a) or any previous version of MATLAB. When I attempt to execute the function in an earlier version of MATLAB I receive the following error:

 ??? Invalid MEX-file 'H:\Documents\yprime.mexw32': The specified procedure could not be found.

Answer 1

[MathWorks Support Team]

This is expected behavior. MEX-files are generally backward compatible but not forward compatible.

A MEX-file created in a given version of MATLAB generally works in subsequent versions. However, MEX-files created in any version of MATLAB are not expected to run in an older version. In some releases, you may find this will work; however, MEX-files compiled with MATLAB 7.3 (R2006b) do not work in previous versions due to a restructuring of the MEX API.