Error calling tune on subdevice in GRC


I had an “Error calling tune on subdevice” in the RX 750-1050
while I was running “usrp_two_tone_loopback” in GRC. It was working
successfully but I touched my SMA Antenna and suddendly it began to fail
when I tried to restart the program, the system gave me this error. I
something must be wrong with function “tune”, but I don’t know what to
do in
order to solve the problem. Any idea? Thanks in advance!

Álvaro Fernández-Villamil