.plugin works great on mac unless zipped then unzipped

I have created a plugin for After Effects, and so far its working great on both windows and mac.
However, on mac when I prepare the plugin for download by zipping it, then a user unzips it again it causes an error when trying to use it: “Cannot find entry point”.

This does not happen if the .plugin file is transferred to the user’s mac with USB drive. It only happens when the file is zipped and then unzipped.

Has this happened to anyone else?