[Barrow4491]

Hi Mike

It isn't due to having changed of the LCD, that you started to get compile errors, it must be something else.
Check if you haven't changed the library, or if you are using the one suplied with the software.

Your new LCD may have a diferent I2C address than the one defined by default, however this not cause any compile error, just the LCD doesn't display any data until you set the correct I2C address.

If you don't know the I2C address of the new LCD, use the I2C scaner utility. By defaut it is set to 0x27

By the way, latest AQM software is v7.1_b003

Werk 
Sorted it out.Yesterday I was working on another project which needed "LiquidCrystal_I2C" and the one supplied with your software is named "LiquidCrystal-I2C", so I had both in the Arduino library.
When compiling it opted to use the more conventionally named one with the underscore rather than the dash.
I have deleted the other and changed the address to 0x3F and all is good now
Thanks
Jim