MFRC522: Firmware Unknown
The mention of unknown in the output line:

Firmware Version: 0x1C = (unknown)


isn't a good sign.

Run the firmware_check example to verify that first, before trying to run other code.

The unknown is output by line 1302 of MFRC522.cpp:

    default:   Serial.println(F(" = (unknown)"));


The firmware_check example states on line 49:

  Serial.println(F("Only known versions supported"));


So, your hardware (i.e. the reader) may not be supported. 

The only thing I can suggest is try another reader. Also, read the README, there maybe some thing there, or contact the author and/or raise an issue to see if you can get support for your version of the firmware (0x1C) added.