HACKRF_ERROR_NOT_FOUND

I have connected my HackRF to my computer that runs Ubuntu and it was working fine until now. It gives me an error:

FATAL:Failed to open HackRF device(-5) HACKRF_ERROR_NOT_FOUND


Has anyone had the same experience?

Try using the HackRF as root to determine if it works. Also try adding yourself to the dialer group in /etc/group - that works for me with my SDR dongle. What's the dmesg output when you plug it in?