Getting build errors after adding app_uart_fifo.c


I had a building project until I added app_uart_fifo.c. The app fifo and uart flags are enabled in the sdk_config.h. This is a custom board. Now when I build I get the following errors:

    Output/Debug/Exe/TagIt.elf section `.nrf_balloc' will not fit in region `UNPLACED_SECTIONS'
    region `UNPLACED_SECTIONS' overflowed by 28 bytes
    Output/TagIt Debug/Obj/app_error_weak.o: in function `app_error_fault_handler':
    undefined reference to `__start_log_const_data'
    Output/TagIt Debug/Obj/nrf_log_frontend.o: in function `nrf_log_frontend_dequeue':
    undefined reference to `__start_log_const_data'
Build failed