Database corruption after mobile save: "Bad Database Structure" & "Invalid Format" errors

[lilith jones]

Hello everyone,

I am seeking technical advice regarding a severe database corruption issue on a KeePass 2.x (.kdbx) file.

Context & Environment:

• Main database file used on Windows (KeePassXC) and Android (KeePassDX via GrapheneOS).
• The database is secured using a Master Password combined with a local Keyfile.

How the Corruption Occurred:
Earlier today, while editing an entry directly on my phone, the mobile application crashed or encountered an unexpected process termination exactly during the save routine.

Symptoms & Error Messages:
When attempting to access this specific file snapshot now on any platform, the database fails to decrypt. The applications return explicit variations of:

1. "Bad database structure / invalid format"
2. "Corrupted file / Keyfile invalid" (likely a false alarm triggered by structural header damage).

Recovery Steps Already Attempted (All Failed):

1. Tested the keyfile against an older, uncorrupted backup copy of the database on my PC. The keyfile works perfectly fine, confirming the physical keyfile itself is intact.
2. Attempted to run the file through classic KeePass 2.x on Windows using the native "KeePass KDBX (2.x) (Repair Mode)" import option. It generated an empty placeholder folder structure with default sample entries, failing to parse any actual data rows.
3. Ran a raw text-scraping utility (findstr) against the file binary to see if any readable string headers survived, but the output was entirely randomized cryptographic noise.

It appears the file was abruptly truncated or experienced a partial/incomplete block write to the flash storage mid-save, destroying the unencrypted cryptographic headers.

Questions for the community:

• Are there any deeper CLI block-parsing tools or hex-editing methodologies available to manually patch or bypass a broken header flag if the underlying data payload blocks are mostly intact?
• Given that the native KeePass 2.x Repair Mode import returned empty folders, does this indicate that the data payload blocks themselves were fully wiped or zeroed out during the mobile crash?

Any technical insights would be greatly appreciated. Thank you.

[wellread1]

If the native KeePass 2.x Repair Mode returned an empty folder then nothing could be recovered by KeePass. You can check the size of the database on disk. If it is zero or significantly smaller than the original or recent backup the corruption is profound. Regardless of the database current size, there is nothing to be done if Repair mode failed.

Since you are not using KeePass it is difficult to suggest a course of action however if you are saving your database to a cloud service then there may be a previous version of your database in the cloud service. Check the service for file recovery options or terms such as "previous versions" or similar.

Since the problem appears to originate with KeePassDX on Android (not KeePass a Windows program) you might want to check out the KeePassDX github repository for help at https://github.com/Kunzisoft/KeePassDX/releases