We have bought new 962UiGS-5HacT2HnT for a project.
As I have many different routers and switches from Mikrotik installed not only for my company
I am accustomed to leave some files laying in flash memory as long I need them.

With this model, after reboot those files are deleted. Is that normal behavior? I have downgraded and
upgraded to the latest but this remain the same. Even certificate files for OVPN are gone.

BTW, OVPN was faulty in the beginning. I had problems with TLS then after many different try and error
attempts and after one disable all OVPN config action everything auto-magically started to work as it should. ???
Never had such a problem before.

# sep/07/2017 10:01:17 by RouterOS 6.40.3
# model = RouterBOARD 962UiGS-5HacT2HnT

All that's not in the flash folder is deleted on reboot

This type of equipment has only 16MB of flash. Everything you save in "/" is actually saved in RAM in fact. If you want to keep files save them in "/flash" but be careful that the space is limited.
Or add a USB stick and save it there.

https://wiki.mikrotik.com/wiki/Manual:System/File
"Warning: If device has a directory named "flash" in its file list, then files which you want to be kept after system reboot/power cycle must be stored within it. As anything outside of it is kept within a RAM disk and will be lost upon reboot. Note: this does not include .npk upgrade files as they will be applied by upgrade process before system discards the RAM drive content. "

I can only say thank you for quick answer. To be honest, I expected something like that. If need arises to store files I will point my colleagues to insert USB
storage.