When I run audacity I get the following error message:
The system has detected that another copy of Audacity is running. Running two copies of Audacity simultaneously may cause data loss or cause your system to crash.Use the New or Open commands in the currently running Audacity process to open multiple projects simultaneously.
I checked the system's monitor and there is NO audacity process running. At least not one that I can spot.
I rebooted and nothing happened.
killall audacity
from a terminal window. Or simply log out and back in or reboot. – Byte Commander May 19 '17 at 14:34