The filesystem can be thought of as a journal which keeps the track of how the computer writes the data in your HDD or SSD storage devices, And in some unfortunate cases, a common one, for example, the computer got shut down improperly, which result in the OS not able to keep up writing to the journal, as a result in data loss or filesystem corruption. Fortunately, there are ways to recover the journal.
Steps to recover from the situation:
Prepare a bootable Live USB drive or external disk that you can boot from
Check the filesystem by using
2.1 Open Disks
2.2 Select the system parition label with ostree
2.3 Click on the drop down menu under beneath the parition layout
2.4 Select 'Repair filesystem' and wait
Reboot the system once the file system checking finished without any warnings.
Alternatively you can run from Terminal with this command to fix the parition: