Hello Johnwhetstone, 

Thanks for posting your question on this thread, so your right 2016 is not compatible with MTD, you would have to upgrade to 2021 desktop version however Desktop is discontinuing and you will no long be able to use it at all or have access to it, so you would need to either move have to move to online or to a different soft ware completely. Do you have a subscription for your 2016 desktop currently?