Last time I had used MQX3.8 RTOS. It was working properly. Then i upgraded to MQX4.2. I am using K60 kinetics MCU pins PTE24 and PTE25 for UART communication. Some Times the MCU is hanging, even though I set OSC1_CR = 0 and MCG_C10 = 0. I disabled UART communication, then there is no MCU hang issue. How to solve MCU hang issue.