UARTPPS

The UART1 and Console modules assume that the RX and TX pins have been correctly assigned by the Firewing loader at startup. That is, when the microcontroller has been reset. However, if the Firewing loader is not used (for example, when programming the target device directly using a hardware programmer) then these pins should be configured manually.

You can easily do this in your main program OnStartup() event handler, like this:

' configure TX and RX pins on UART 1...
sub OnStartup() Handles PIC.OnStartup
   RPINR18 = RPINR18 and &HFFE0 or &B00100  ' map Uart1 RX to D0 (RB.4) 
   RPOR2 = RPOR2 and &HE0FF or &B00011 << 8 ' map Uart1 TX to D1 (RB.5)
end sub

Alternatively, you may want to disable the UART on pins D0 and D1 altogether, like this:

' disable UART1 on pins D0 and D1...
sub OnStartup() Handles PIC.OnStartup
   RPINR18 = RPINR18 or &H001F  ' disable Uart1 RX
   RPOR2 = RPOR2 and &HE0FF     ' disable Uart1 TX
end sub