protocol error, expect=0x14, resp=0x50 - this part of the error message says that the configuration is expecting a different chip, or version of the chip. The chips have a couple "signature bytes" that AVRDudue checks to see if the correct chip is connected and the signature isn't correct. May not be a problem - ATMega328 and ATMEGA328P do this.
What system are you using this on, and how comfortable are you playing around with a DOS prompt?