can't open USB device

Dear collegues, could you help me to start using SIMtrace board? I have bought SIMtrace board v1.4 from symocom shop. I have got sources from github but cannot (it is strange) built user manual on my ubuntu computer. BUT I am successfully built simtrace application but it cannot recognize the board.

user@lnkd149:~/OSMOCOM/simtrace/host$ ./simtrace simtrace - GSM SIM and smartcard tracing (C) 2010 by Harald Welte <laforge@gnumonks.org>

can't open USB device

that message I have received on my screen... Could you advise something? regards Alex