So their drivers for 10.10.x don't fix that? Well if you aren't looking for a solution, then that's cool, but I'd wager that the problem can be solved. Heck, I got my neighbor's all-in-one working after the manufacturer failed to provide driver updates for Yosemite. It was a simple Terminal command that "softened" the sandboxing restrictions on an existing driver. Or something to that effect. He was dumbstruck when I found and applied the fix in minutes.
I have installed drivers to the point that I am about to run out of electrons. But I didn't expand on the problem. It has something to do with the Thunderbolt display. With it plugged in the machines BSOD. Without it, they don't. I even borrowed another TB display to see if mine had some defugalty. Failed with borrowed one also.
(By BSOD, I mean an actual crash, just as if they had bought the app from MS. Within, say, ten minutes or so, or ten seconds, an instant blank screen appears with the message, "Your machine has hard crashed. Sorry about that." Or words to the effect.) I have had kernel panics on Linux before when, either I, or some hardware really screwed up, but after seven years of using Apple, I didn't even know that a Mac could get a BSOD.
Two fairly new Macs - one desktop and one laptop - two TB displays and they fail. I have swapped out the external wireless keyboard and mouse for wired. Unhooked everything that can be unplugged - Network, DVD, Time Machine, USB hub. Turned off wifi and tried booting without anything loading except what the system needs.
Unfortunately I don't know anyone else with a Wacom.
Take off Yosemite, it runs just like it has for years.
I will gladly take advice if someone has any insights. Maybe a new chair, or change from Dr. Pepper to Coke? Cut out more carbs? Anybody?