Errors occur when the shared library is not a valid library. MATLAB® displays messages similar to the following:
There was an error loading the library "F:\mylibs\testlib.dll" 'F:\mylibs\testlib.dll' is not a valid shared library.
There was an error loading the library "/home/myname/testlib.so" '/home/myname/mylibs/testlib.so' has different architecture than the host.
If the library has dependencies which MATLAB cannot find, then MATLAB displays messages as described in Invalid MEX File Errors.
On Windows® systems, to find library dependencies, use the third-party product Dependency Walker. Dependency Walker is a free utility that scans Windows modules and builds a hierarchical tree diagram of all dependent modules. For each module found, it lists all the functions exported by that module, and which of those functions are called by other modules. Download the Dependency Walker utility from the website http://www.dependencywalker.com. See http://www.mathworks.com/matlabcentral/answers/92362-how-do-i-determine-which-libraries-my-mex-file-or-stand-alone-application-requires for information on using the Dependency Walker.