Prepare for reboot...?

IPFire C138 is installed on a: HUNSN Firewall (Intel Quad Core J1900,(Gray), RS17,4 Intel Gigabit LAN/2USB/1VGA/Fanless/2 Reserved Fan,(2G RAM/32G SSD).

When I try to reboot, IPFire hangs on: Prepare for reboot…

Any suggestions?

This is a hardware issue and a BIOS update might help.

I cannot find a BIOS-Download for the NSM-J1900-6L Motherboard…
BIOS Date is 07/15/2019, maybe there is some special config?
Is there another way, maybe a Kernel/GRUB Tweak?

No. The boot loader is not involved in shutting down the system.

The kernel is simply sending an ACPI signal to the BIOS and that will take care of switching off power.

OK, but why can other OS reboot?

Edit:

BIOS > Advanced > Miscellaneous Configuration > OS Selection

You can choose btw Windows 8.X, Linux, Windows 7

I choosed Linux and now the Device is able to halt or reboot!

Thank you very much, I appreciate you help and work for IPFire!