You do not need 3 lines of code to start tim14 in Lesson 4 (PWM example). one line is enough: HAL_TIM_PWM_Start(&htim14, TIM_CHANNEL_1);
You do not need 3 lines of code to start tim14 in Lesson 4 (PWM example). one line is enough:
HAL_TIM_PWM_Start(&htim14, TIM_CHANNEL_1);