We ran into this issue as well. If I was using any other stack cable besides the cisco ones, when the switch updated to 10.x it would fail. Luckily out of the dozen or so stacks I have throughout the building only two of them were using non-cisco cables.   I was able to replace the one stack with some meraki cables, but the other one we don't have any long cisco cables on hand to stack with. Luckily it doesn't have to be stacked, so I'm just running them independent for now.   Gave me quite the headache for a day trying to track that problem down (which included RMAing the 4 switches in question). ... View more