why a dll work Matlab 2012a but not 2012b & later

A custom dll were used in Matlab 2010a. It works properly. However, the dll does not work anymore when it is used in Matlab 2015a. Could you please tell me how to sort out this problem? Many thanks

[Jan]

Please provide any details about "does not work" to increase the chance to identify the problem.

[Adam]

Something probably changed between R2010a and R2015a

[John D'Errico]

Surely you cannot be surprised. Things change at that level between releases. Recompile the code, or re-write it.

This is the virtue of m-files. I have 25+ year old m-files that still run just perfectly, despite dozens of releases in between. That simply will not be possible with compiled code.