RaspberryPi & Gnuradio

Hi everyone,
I am trying limesdr with RPi and I installed each driver and OOT module without any problem and tried to open test self test.ini on LimesuiteGUI, I saw [error]write(64bytes)failed. I also tried with gnuradio basic flowraph consisting of osmocom source and gui sink 500k samp rate and get the same error. Any ideas?
Thanks

Problem communicating with the board, could be that raspberry pi does not supply enough current to properly power the board, you should try powering the board with external power source