File Corruption resulting in file containing mostly zeros or other incorrect data: "This file is either not a Prism file or its structure has been corrupted."

The Problem

On rare occasions, when opening a Prism file, you may see the error message “Cannot open file. The file is either not a Prism file or its structure has been corrupted”.

This issue may occur when data structures within the Prism file are filled with zeros. If you look inside such a .prism file with any hex editor or with a text editor for legacy Prism formats - you may see that parts of the file, or the whole file contain zeros or other incorrect data. Note that we have only observed this issue on Windows.

Why does this happen?

This issue is common to many different file types (not just Prism files) and may occur to any file on the device. There are a few possible reasons that can cause this issue to occur:

Power loss or an unexpectedly unplugged drive

• Sometimes, during a power loss, the system is able to save the file, ensuring that the structures are stored on-disk correctly. But the data of the file may be lost. If power is cut during a write operation, files may appear intact upon remounting (because their structures are intact), but their data could be corrupted, potentially resulting in zero-filled files.

• The same can be expected when a drive where the file is saved is unexpectedly unplugged (like pulling out the USB cable).

Here are a few reports in which files from other applications experienced the same issue:

What could cause files to end up zeroed out?
Recover a file filled with zeroes (nuls) after power loss
Zero filled file on power cycle

Broken archive, probably due to some kind of encryption on the drive where the file is saved

• If the drive is encrypted and there are errors or issues with the encryption process or keys, it can result in corrupted files.

• If there are compatibility issues or conflicts with the encryption software or algorithms used to encrypt the drive, it can result in corrupted files.

• If the encryption process is interrupted or not completed successfully, it can result in incomplete or corrupted encrypted files.

You can find more details on these pages:
How to fix possible corrupted files from decrypted drive?
What is difference between corrupted and encrypted data files?
If a tiny part of encrypted data is physically corrupted, does it mean the whole data is now unrecoverable unlike recoverable plain data ...

Problems during file transferring (e-mail, file uploading and downloading, network, cloud etc.)

• Errors or glitches in the software used for transferring files can result in file corruption. This can include issues with email clients, file transfer protocols, or cloud storage services.

• Network issues or interference can lead to errors in data transmission, resulting in corrupted files. For example, if there is a sudden interruption or drop in the network connection while transferring a file, it can lead to incomplete or corrupted data.

Here is what we have found from the reports from other users:
FIX: Large files become corrupted during file transfer through the Socks V4 client - Microsoft Support
Can file transfer errors between devices cause MTS file corruption, and if so, what precautions should be taken?
File Corruption During Network Transfer - Windows 7 Help Forums
What are zero-byte files and how do I deal with them? - GoldFynch Blog

Problem with the hard drive, where the file is saved (or other storage)

• Disk errors or issues such as disk fragmentation, read/write errors, or disk failures can also cause files to become corrupted and contain zeros.

• A hard drive can develop bad sectors over time due to physical wear and tear or other factors. When a file is saved to a bad sector, the data can become corrupted and may contain zeros or other incorrect data.

Here are some of the discussions on this topic:
Can leaving a corrupt file on a hard drive cause damage to the drive/other files?
If a hard drive has sectors that are corrupt or physically damaged, can those sectors be written over?

What can I do?

• You may want to enable the file history feature on Windows. If you use Windows backup systems and File History, try using the tips from this page: Backup and Restore in Windows.
• Verify that you have a stable internet and network connection
• Contact your IT team to verify encryption methods and to determine if this may be the cause of file corruptions
• Check the file system to determine if there are issues with the hard drive - chkdsk

If you suspect that a file has become corrupted and contains zeros due to a problem with the hard drive or other storage media, it is important to stop saving files to the drive to prevent further data loss or damage and contact your IT team.

Other tips and possible reasons for file corruptions can be found here.

If you are having trouble restoring a file, you may contact our support team and we will do our best to help fix the file and restore any recoverable data which was not replaced by zeros. We will also work to improve Prism so that it is capable of automatically opening such files, removing corrupted data and recovering what remains.