Solved
Cube L4 V1.13.0 LL__RCC_DeInit() failed in release
I use Atollic TrueSTUDIO v9.0.1 for a STM32L496RG project.
I use the LL_RCC_DeInit() function and have an issue when activation of Optimisation option -Ofast or -O3 .
To fix the issue I had to add the key word volatile (see code below).
ErrorStatus LL_RCC_DeInit(void)
{
// uint32_t vl_mask; // RCC register not changed when opitimzation -Ofast or -O3
volatile uint32_t vl_mask; //FIX to run with opitimzation -Ofast or -O3
/* Set MSION bit */
LL_RCC_MSI_Enable();