During initialisation, the screen does not work after the MPU initialises and I was wondering if the two devices do not work together well.
I am thinking that its something to do with the libraries clashing and not working well together.
As you didn't provide links to the hardware you're using (I guess you don't use the chips directly but on some breakout board, these boards contain other components) as well as no wiring diagram of your setup we first assume that it's a hardware issue. Did you try the same hardware setup with just one of the two libraries? Did that work?
Did you modify the I2CDevlib? What type of Arduino are you using? Does your setup include additional hardware?
Post the necessary information.