Priorities assert in vPortValidateInterruptPriority

See RTOS for ARM Cortex-M and e.g. this post Understanding priority levels of ISR and FreeRTOS APIs - #16 by aggarg (there are more here in the forum) for the necessary details to setup interrupt priorities (on Cortex-M) right.
INT prio 0 is definitely wrong to be used with FreeRTOS API calls in the corresponding ISR.