System.Threading.Timer continuing to run after software and firmware update - Panda II

I wrote a program recently that started a TimerCallback, which periodically printed out “No Signal”. Since the, I’ve deployed a different piece of software, and gonr through the firmware update procedure. Yet I still get “No Signal” printing periodically in the Output window.

What did I do that made the Timer keep going, and how can I stop it!?

Hard to say without looking at your code.