I will check my code an other time..
I also investigated the power supply: nothing conclusive.
The crash is random in time, but always at the same place / same message. And when it happens it is very likely that it repeat every 15 / 20s. But this may happens after 20mins of run, with the same ...

I have the following random crash, on an ESP32C3 sometimes after several minutes of perfect results
assert failed: xQueueReceive queue.c:1540 (!( ( xTaskGetSchedulerState() == ( ( BaseType_t ) 0 ) ) && ( xTicksToWait != 0 ) )
followed by registers + stackdump.

Unfortunately it is difficult to ...

I have rmt_transmit ongoing , sending always the same pattern ( loop count = -1 in the transmit configuration)
Now and then I need to change the pattern but only when the previous pattern is fully transmited.

The transmit is stopped by rmt disable() but it seems that the transmit is stopped ...

Perfectly clear. Thank You for the explanation.

A classical way to setup a timer is for eample

hw_timer_t *My_timer = NULL;

My_timer = timerBegin(0, 80, true);
timerAttachInterrupt(My_timer, &onTimer, true);
timerAlarmWrite(My_timer, 1000000, true);
timerAlarmEnable(My_timer);

If this code is in a small init function, do we need to declare ...