SPIS Nrf log enabling problem

[Ozil 11]

I'm trying to print received data on my com port but when I set the  "NRF_LOG_ENABLED" as 1 the error below shows up.

.\_build\nrf52832_xxaa.axf: Error: L6218E: Undefined symbol nrf_log_default_backends_init (referred from main.o).
Not enough information to list image symbols.
Not enough information to list load addresses in the image map.

What does it mean?? How would I know what files to include. I then though I could use "printf()" command to do the same but it shows similar error. I included all the files which support uart into it. I'll mention below just to be sure:

In nRF_Drivers:

app_uart_fifo.c

nrf_drv_uart.c

in Libraries:

app_fifo.c

I included the path of those drivers and libraries too.

[Martin Lesund]

Have you tried a standard unmodified example (like "ble_app_uart") and see if you can read out logs at all on teraterm?

[Ozil 11]

Yes, thank you. I can see the logs in teraterm of "ble_app_uart". I will use this as reference and modify my SPIS example of the sdk