Failed to boot after 6.37 update

I have a routerOS for my x86 router. Recently I got problem in the update to 6.37. Upon restating after downloading, the router loses its connection i..e failed to boot up. Screen output showing directory / file missing. When I took out the msata and put it into a USB external drive, it boots but with licence expired.

I think the file got missing or corrupt during the OS upgrade. How I can fix it?

I want try netinstall but worry about the configuration files lost.

In netinstall I think there is an option to keep the old configuration.

I fixed the issue with ISO image to reinstall. Netinstall does not work at all.

ISO image installation has an option to keep old configuration. Only issue is that it formats my 128GB SSD.

Fortunately, it is x86. I took out the SSD and mounted it under a linux image. I managed to copy all the files including the licence key file first