Why do you have two spurious flying leads going to the "LED" pins where the enable jumper is supposed to be?
The library you cite appears to be for a quite different "backpack" and therefore not recommended:
It is then no surprise that it is not working if the only descriptor you are using is:
LiquidCrystal_I2C lcd(0x27,16,2); // set the LCD address to 0x27 for a 16 chars and 2 line display
We can only recommend that you use the more familiar fmalpartida library (and remove any and all other LiquidCrystal libraries from your IDE path) and then use bperrybap's "i2cLCDguesser" script to determine the correct descriptor to use with this display and backpack, which descriptor you then copy into whatever sketches you want to use.