KernCO1234, good afternoon, unfortunately mac's are not supported with this version for this topic. In fact, the latest product of removable storage(SEE 11.0.1 mp1) just provided support for the removable media encryption access utility for Mac. Here is a link on that: https://support.symantec.com/en_US/article.TECH224480.html
I would recommend that you decrypt all files to your local windows desktop with the GERS access utility, then install the latest version(SEE 11.0.1 mp 1 RME), then re encrypt for compatibility.
Hope that helps