Error on tx_usrp example

[JaymeNeto]

Hi I'm trying to use gr-lora with an USRP N210, but when I run the tx_usrp. I'm always receiving this error message:

Warning: failed to XInitThreads()
linux; GNU C++ version 7.3.0; Boost_106501; UHD_003.010.003.000-0-unknown

Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock

Could anyone please help me?