Error message on EXIT_SAPMM06E_012 disable screen

Hello,

In transaction ME31K I need to process error messege on saving. In EXIT_SAPMM06E_012 when I write a message it makes all the header screen field disabled,

when I press Enter the exit EXIT_SAPMM06E_012 is called again and show the message again.

The only way to change the layout to editable again is to exit the header screen and enter to the header again.

Is there another point to process error message on saving\check or another way to show the user message and stop saving porcess?

Thank you !!!

Yotam.