Hi Brendan,
Hope you are doing good.
Thanks for your query !
I am assuming that you are using SHK/Sentinel SuperPro/Sentinel UltraPro Key. Please confirm and share the type/color of Sentinel HL key(USB Device) being used.
It appears that the Sentinel System drivers are in place. However, it is always recommended to use the latest drivers.
Please find below the link to download and install our latest Sentinel System Drivers v 7.5.4
Kindly note that these drivers are officially tested for MAC OS 10.11 EL Capitan and earlier version. Try installing the same on MAC OS Sierra and share in case any issue appears.
Refer to the methods mentioned in attached picture in order to verify the presence of Sentinel System drivers.
Hope it helps !
Please feel free to get back to me.
Thank You,
Gaurav Bhanot