I just downloaded the latest FreeRTOS 5.1.0 release and try to run the web demo with lwIP using ARM STR91x. Everything worked well at the beginning and I was able to see the web page refreshed itself. After several hours of running (5-6 hours), the web page could not refresh anymore. It seems that the lwIP stack has stopped responding to any SYN request from the browser. I am not sure whether this a RTOS problem or a lwIP problem. I didn’t change any code except commenting out all the tasks except the “BasicWeb” task in main.c.