OpenSprinkler › Forums › OpenSprinkler Unified Firmware › ESP32 port of 2.1.9 firmware › Reply To: ESP32 port of 2.1.9 firmware June 3, 2023 at 1:02 pm #75937 v1prParticipant @Ray: the error is in the OTF library somewhere 🙁 Do you’ve any idea what can be behind it? assert failed: tcpip_send_msg_wait_sem IDF/components/lwip/lwip/src/api/tcpip.c:455 (Invalid mbox) The error is within somewhere in localServer.begin();