STM32H7 Ethernet using FW V1.10.0 problems with memory?

[PMais.1]

I am adding ethernet connectivity to an existing STM32H743 project and am using the STM32CubeIDE V1.9.0 / STM32CubeMX V6.5.0 and H7 firmware FW V1.10.0. I have followed the guides on setting up the various memory settings and have had success getting a TCP echoserver working. However, I need to modify the responses from the echoserver and as soon as I start to add my code to run the necessary logic to determine the responses, I get memory related problems, causing either a mem_handler fault or failing an ASSERT. The failure I am currently getting is an ASSERT that outputs: Assertion "pc->custom_free_function != NULL" failed at line 767 in ../Middlewares/Third_Party/LwIP/src/core/pbuf.c. I have had a look at where the pbufs are being allocated and they appear to be in the RAM_D1 area. Is this correct and if so, any ideas what is causing this problem? Many thanks.

[wh]

Having the same kind of problem where UDP transmissions stops after a random number of minutes with the Assertion: 

Assertion "p != NULL" failed at line 732 in STM32CubeMX/Middlewares/Third_Party/LwIP/src/core/pbuf.c

I'm running on a STM32H723 processor transmitting one UDP packet ( 8KB payload) every 5 ms. 

Did you find the cause? Or anyone else who had the same experience and came up with a solution? The LWIP stack at least uses a part of the D2 RAM region 

Thanks in advance,

Wim