Wacom Cintiq 21UX DTZ-2100 and OS Catalina

Sorry dude but Wacom announced it has NO plans to update previous generation Wacom product drivers, including the 1st gen Cintiq 21UX (DTZ-2100) because MacOS catalina has moved to DriverKit

The only hope is a 3rd party develops a driver for old wacom tablets, but for now, you're out of luck

So I came across this exchange when I was having trouble with my iMac 2019 running Catalina. I tried all the things that are mentioned in other forums, using dvi to usb-c or using dvi to hdmi to usb-c. I managed to get mine running using a vga connection. On my setup right now I have the switch on the back on the Cintiq to VGA. I have the DVI from the cintiq into a dvi to vga adapter, then connected to an Inland UTC-V01 USB-C to VGA adapter. I used the last driver that wacom issued for the 21UX from 2015 and it works fine. Only issue is that you have to go wacom tablet utility and remove preferences each time you start it that way you can calibrate it everytime you turn on the mac., otherwise the tablet behaves weird. Hope this helps!

I had luck with this 3rd party app:

https://wptrnpt.co.uk/wp/connect-my-tablet/

https://itunes.apple.com/app/id1352696344

my cintiq21ux have same problem. imac27, MacBook Air all can’t work using cintiq.

@.kv No worries! I had a mini display port on my old macbook pro. I'm almost certain DVI-VGA to VGA-Mini displayport adapter should do the trick! good luck!