RTL-SDR No Signal in Gqrx

[Brian Gates]

This is my log... the same error with another question on this group. but different case

this is my log
""

Loading configuration from: "/home/brian/.config/gqrx/default.conf"

Configuration file: "/home/brian/.config/gqrx/default.conf"

gr-osmosdr v0.1.x-xxx-xunknown (0.1.5git) gnuradio 3.7.10

built-in source types: file osmosdr fcd rtl rtl_tcp miri hackrf bladerf rfspace airspy soapy redpitaya 

Using device #0 Realtek RTL2838UHIDIR SN: 00000001

usb_claim_interface error -6

FATAL: Failed to open rtlsdr device.

Trying to fill up 1 missing channel(s) with null source(s).

This is being done to prevent the application from crashing

due to gnuradio bug #528.

********************

********************

No change in output device:

  old: 

  new: 

Failed to set RX input rate to 1.8e+06

Your device may not be working properly.

""

sory for my bad english