Unable to play or record

i am running ubuntu 16.04 and Audacity just stopped recording or playing. Buttons light up but the cursor does not move. Pressing R starts a new track but nothing moves

What were you trying to record?
What audio device are you using?
What settings do you have in the Device Toolbar (https://manual.audacityteam.org/man/device_toolbar.html)?
Are any other audio applications running?