UPB UPE File Gone after RP Reboot

I've come across another issue with UPB.   The UPE file you're supposed to load into the MyServer/Data directory disappears on a RP restart.  No sure if I missed something in the instructions?   This is very repeatable.   I have no idea how to fix it.  Thx

This has been fixed by disabling the overlay file system in Raspi-config.   Go to the terminal, type Sudo Raspi-config.   Navigate tothe file overlay option under "Performance" and disable it.

The overlay file system is an option in raspi-config.  it makes the entire disk read only and everything you do while it is running is lost when it reboots.