Hello all. I'm running mad now. With software serial everything works fine, with hardware serial I can't even compile and get this error:

Code:
#define USE_HARDWARESERIAL
#include <SDM.h>
SDM Plugin_150_SDM(Serial, 9600, NOT_A_PIN, SERIAL_8N1, false);

Error:
undefined reference toSDM::SDM(HardwareSerial&, long, int, int, bool)' sketch/ESPEasy.ino.cpp.o: In functionPlugin_150(unsigned char, EventStruct*, String&)':
undefined reference toSDM::SDM(HardwareSerial&, long, int, int, bool)' undefined reference toSDM::SDM(HardwareSerial&, long, int, int, bool)'
collect2: error: ld returned 1 exit status

Any idea what's going wrong here?