Why is NRF_LOG_DEFAULT_BACKENDS_INIT causing INVALID_STATE error when calling nrf_cli_init?

I tried to use UART both for NRF_LOG and NRF_CLI. Now it's running but I had a problem that calling to nrf_cli_init caused fatal error 8 - INVALID_STATE.

When I commented out the NRF_LOG_DEFAULT_BACKENDS_INIT, the error disappeared and now both LOG and CLI are working.