Thanks for your reply. The trouble I had seems to be specific to 64GB 3.0 Gorilla flash drives. I ordered a four pack of 3.0 Gorilla 64GB, and every single one has had an issue only in my Compass. The Gorillas are also quite slow for USB 3.0 devices. I switched to Gorilla after a previous SanDisk 32GB flash drive got locked into a read-only mode indicating device failure.