RDM M5Stack reboot at discovery

[slechtvalk200]

i use the example arduino_RDMResponder.ino on a M5stack core basic + M5stack DMX. I only change the pin numbers in the example, but when i do a discovery on the "master" device (Swisson DMX tester) , the M5stack core basic reboots en give the error :
assert failed: dmx_parameter_get_entry esp_dmx\src\dmx\service.c:88 (device_num < RDM_SUB_DEVICE_MAX)

what could it be?

using arduino 2.3.2