In file included from HelloWorld.pde:2:
D:\Program Files\Arduino\libraries\LiquidCrystal_I2C/LiquidCrystal_I2C.h:80: error: conflicting return type specified for 'virtual void LiquidCrystal_I2C::write(uint8_t)'
D:\Program Files\Arduino\hardware\arduino\avr\cores\arduino/Print.h:48: error: overriding 'virtual size_t Print::write(uint8_t)'