Microchip MPLAB X XC8: Enable the Peripheral Library
In order to use the peripheral libraries built into MPLAB X a switch must be set in the project properties.
Right click project name from the Projects window and select Properties
Second, navigate through the Categories
[default] -> XC8 global options -> XC8 linker
Third, in the top center of the screen, select Runtime from the Option categories
Finally, scroll to the bottom of the list below and check Link in Peripheral Library