Hey, PlumaLigera! Thank you for including details here! The main concern is that the system is still on OSX Sierra (10.12). Because of the driver limitations for MacOS, the minimum requirement for MacOS is High Sierra (10.13). Here’s the system requirements for Starcraft.
If the system supports it, it’s recommended to upgrade to High Sierra. There are some known issues with High Sierra at the moment though that our team is looking into on this thread.