Most Windows messages are vague, but this one is precise: a record in the Master File Table cannot be read. Understanding what that specific record refers to explains how a single file disappeared and how all the files in a folder and its subdirectories can be lost at the same time.
Every segment of the Master File Table represents a one-kilobyte record for a file. If there are a few records that are unable to be read, then it is due to a local problem on the disk. However, if there are hundreds of unreadable records, the region containing the Master File Table itself is failing. At this point, we have moved on to a different conversation.
NTFS uses a Master File Table (MFT) for storing entries about all files residing on a particular volume. Each MFT entry is a file record segment. In this case, the error means at least one if not more of those file record segments can no longer be read. Therefore, the index used to describe where a file resides has become damaged; that does not mean the file itself has been damaged.
This issue typically occurs during a chkdsk operation or when booting up, and indicates sector-level issues with the area of the disk containing the MFT (Master File Table). Because this area is so small, and used so heavily, we see failures occur here early on failing disks.
The key factor now is what you do after discovering this issue. The general advice for how to proceed has been to allow chkdsk to fix it; however, in many cases, this advice is incorrect.
If the data matters: stop. Chkdsk will repair the file system by discarding any unresolvable data. While it will make the volume consistent, this consistency does not necessarily mean all files are accessible. Additionally, chkdsk writes to a disk that is already failing.
If the data does not matter: let it run. If the volume is a system volume intended to be rebuilt, then allowing chkdsk to potentially make it bootable again is a valid option.
Either way, check the drive health. This type of error is rare on healthy drives. Before taking any additional action with your drive, review the SMART data from your drive. Reallocated or pending sector counts rising indicate you have a hardware issue.
Do not repeat it. Running chkdsk repeatedly worsens problems on an already failing disk with each run.
Only if you are willing to accept that all items which cannot be reconciled will be lost. Chkdsk prioritises the integrity of the file system over your files.
Generally, yes. The Master File Table (MFT) area degrades early due to its limited size and constant writes; but do a SMART check before assuming otherwise.
Often. The records describing them are damaged, but there are many times when the information itself is still intact and can be accessed via another method.
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