Compatibility of a custom library compiled under Matlab 2011b with Visual Studio 2013

A custom library compiled under Matlab 2011b worked in Visual Studio 2010 but won't work in VS 2013. Does the library need to be recompiled? If so, is it a switch setting that needs to be adjusted or is a different version of Matlab needed? If a different version, will Matlab 2013b work or is another vintage of Matlab needed?

[Steven Lord]

Please clarify what you mean by "won't work in VS 2013." Does it throw an error (and if so what is the full text of that error) when you try to use it? Does it issue a warning (and if so what is the full text of that warning?)

Is the "custom library" a MEX-file that you compiled with VS 2010 previously and are now trying to compiler with VS 2013? Is it an application generated using MATLAB Compiler? Is it source code generated using MATLAB Coder? Is it something else?