This screen indicates a serious filesystem error on your Linux/Mac system that prevents it from booting normally. - Manual Repair Required: The operating system has stopped and requires you to manually run a filesystem check (fsck) to fix errors on the partition /dev/sM
- Action Needed: At the (initramfs) prompt, type fsck -y /dev/sda2 and press Enter. The -y option will automatically attempt to repair all found errors.
- Final Step: Once the repair process completes, type reboot to restart your computer.
- Hardware Warning: If these errors persist or keep returning, it may indicate that your hard drive or SSD is failing and needs to be replaced.
*** more info on the filesystem check
*** NOTE: the initramfs prompt initiates temporary tools which mount/make work the real root filesystem. It works between user and root, contains binaries, driver and scripts required for network booting.
I hope this helps - it's right out of the manual.
Personally, the instant it works, I'd suggest backing up all your data as a first action.
Best wishes,
Ellin