We have encountered two simple API changes recently, but they each can cause some confusion.
Image Sample issues
The first one is the image extension sample in Maya devkit. It is used for creating image extension for adding extra image format support in Maya. It is located in devkit/image folder.
It appears above mentioned sample and its document haven't been updated for a while, and there are two small issues inside of it. Imf.lib is renamed to imfbase.lib now and the project is missing a preprocessor definition (PLUGIN_DLL).
registerCommand in Maya 2016.5
In Maya 2016.5, if you are registering a command with MFnPlugin::registerCommand without giving a newsyntax function. Maya will call creator of your command.
For example, following code is taken from blastCmd sample in Maya devkit.
I've tested with Maya 2016, Maya 2016.5 and Maya 2017 Update 1, this problem only exists in Maya 2016.5. If you are going to build a command plugin for Maya 2016.5, please take it into consideration.