Testing reactos-bootcd-0.4.14-dev-1222-g94f6db2-x86-gcc-lin-dbg in VirtualBox 6.1.4:
Installing from the boot CD to a fresh VM (RAM: 512MB, HDD: 20GB) whole disk – one primary partition.
1st stage: ok, bootloader - MBR+VBR;
the first attempt:
1) Loader shows choices for booing (selecting ReactOS)
2) Enters graphic mode, passes the Logo stage (without any visible issues), clears the screen and displays the window with the text "InitializeProfiles() failed. Rebooting now!" in the light blue background. Pressing the "OK" button closes the window and nothing goes further (neither the system reboots, nor installation proceeds).
(resetting the virtual machine)
The following attempts to continue with the installation:
1) if the file system is FAT:
a) Loader shows choices for booting. The choices "ReactOS", "ReactOS (Debug)", "ReactOS (RosDbg)", "ReactOS (Screen)", "ReactOS (Log file)", "ReactOS (Emergency Management Services)" results in a bootloader crash (see the second screenshot).
b) The boot option "Unknown Operation System" either results in a black screeen or crash the VirtualBox with Guru Meditation (happened for me only once).
2) if the file system is BRTFS, everything happens like at the first attempt.