LiquidCrystal_I2C Arduino Due

[ard_newbie]

WARNING: library LiquidCrystal_I2C claims to run on (avr) architecture(s) and may be incompatible with your current board which runs on (sam) architecture(s).

I guess you included an LCD Library for an AVR ?

Examples of LCD via I2C over a DUE:

Arduino Due and I2C LCD example - ARM Learning

Clock and calendar using Arduino due internal RTC and I2C LCD display