Why do I receive the warning "library class already exists" using LOADLIBRARY in MATLAB 7.0 (R14)?

When I run the following code:

hfile = [matlabroot '\extern\include\matrix.h'];

loadlibrary('libmx.dll', hfile)

I receive the following warning:

 Warning: The library class 'libmx' already exists

Answer 1

[MathWorks Support Team]

This warning occurs in MATLAB 7.0 (R14) and later due to the fact that the library class has already been loaded.

To prevent this warning, use the UNLOADLIBRARY command:

unloadlibrary libmx

hfile = [matlabroot '\extern\include\matrix.h'];

loadlibrary('libmx.dll', hfile)