STM32L100RC and STM32L152RC disco boards fail on LL_FLASH_GetLatency() != LL_FLASH_LATENCY_1
Ok, I think I found it - as stated in HAL &amp; LL manual for L1 at page 1088 for LL_FLASH_SetLatency function: 


  Latetency can be modified only when ACC64 is set. (through function
  LL_FLASH_Enable64bitAccess)


And this function call is missing in generated cubemx project. I found it, when I looked at LL GPIO example for stm32l152re nucleo board (as there is no LL example for stm32l100rc and stm32l152rc disco boards), where this function is used.

Adding it before LL_FLASH_SetLatency in SystemClock_Config solved it, and the LED now blinks (at least at l100 board, didn't try l152 yet).