Apologies, crash may be in xPortStartScheduler, but it looks like it crashed on entering StartFirstTask. Background: STM32F429, STM32cubeIDE, FreeRTOS V10.0.1 as supplied by STM’s “Cube”. Optimization -O1 (except trap handler for register visibility) define configUSEPORTOPTIMISEDTASKSELECTION 0 Not using static allocation option. systick timer for FreeRTOS, peripheral timer for Cube timing utilities. Detail: Debug builds and runs application AOK. Plenty of memory (FreeRTOS pool, newlib heap, stack). Registers in fault handler: Stack, code dissasembly: Much obliged for any ideas where to look… Thanks! Best Regards, Dave

Sorry, solved, problem was wrong library specification. Release newlib selected was Reduced C, Reduced C++ (should be Standard C, Reduced C++). Application works with correct library selected. Not sure why this causes a crash here though… Aaarrrggg…