does not work

[sanluca]

hi , I have a problem with the first example of MQTT client , I did everything according to the debugging scheme, however esp8266 lights when part Arduino and turns off immediately after flashing blue LED , only if I unplug the d4 from Arduino esp8266 stays on . if I leave the d4 connected , debugging gives me this :

\0xc4\0x1c\0x12aA\0x9a\0xde9\0x97\0xcd\0x11S\0xf0\0xdekcAO\0xc4\0xe3\0x97\0xc6\0xdb\0x9c\0xd5\0x17\0xc1\0x94]\0x13\0xda\0xb1\0x94\0xd8/CNAu\0xc1\0xdb8\0xd5\0x8a\0xd3^\0x10\0xf0\0x14B\0x91\0xe2\0x13\0xf8\0xdb8\0xd5\0x8a\0xff\0x85\0xd8\0x91

what can I do? thank you