¶ Cause
There are a couple of unavoidable scenarios that will result in partition loss or corruption, at the moment like that, the bootloader will having problems finding the main root filesystem, and you will see something like this:
¶ Resolution
In order to resolve this situation, please check the solutions below:
A. Boot into any Linux Live USB and mount the root filesystem and create/write any files, then shutdown and boot the system it will work again, following as an example,
Open any terminal app
Mount the root parition labeled with "ostree":
$ ls -l /dev/disk/by-label
$ mkdir ostree-root; sudo mount /dev/sdb1 ./ostree-root
Touch or create any file:
$ cd ostree-root; sudo touch /root/any-file
B. Alternatively, reinstalling EOS with a newer version, 3.8.4 or late, will avoid this bug going forward.