This tip will show you how to use MCUXpresso Config Tools V4.1 generate codes for KV5x with 50MHz external reference clock.
The fec_extal in datasheet shows that the maximum frequency of Input clock frequency (external clock mode) is 48MHz.
It will lead code generation failed when you configure 50MHz as the external reference clock in latest MCUXpresso Config Tools V4.1. (Code generation in case of warnings shouldn't be blocked. It will be fixed for MCUXpresso Config Tools V5.)
Some customer had met this issue when using TWR-KV58F220M board, this board connect a 50MHz_OSC to EXTAL0.
My colleague have prepared a hot fix for this issue (for all MKV5x MCUs). After install the attached hot_fix_MCUXpresso_Config_Tools_V4_1_data_MKV58_MCUCM-3936, customer is able to overcome it.(Notice: The ProgramData folder was hidden by default.)