My .kbk backup won't restore

Wrong passphrase, unsupported version, or an unreadable file - what each restore error means and what actually fixes it.

A .kbk backup is a passphrase-encrypted file you own - Kochab never holds a copy of it or the passphrase, so restoring it always starts with picking the file and entering the passphrase yourself on the Restore screen. The message it fails with names which of the following went wrong.

“Wrong passphrase”

This means the file decrypted incorrectly under the passphrase you typed, not that the file itself is bad. Kochab may have prefilled a remembered passphrase from a previous restore on this device. Check that the field holds the phrase you used for this particular backup, especially if you have made more than one over time with different passphrases.

“Unsupported backup version”

Kochab could not recognize the file’s header. This usually means the .kbk came from a very different app version than the one restoring it. Update Kochab to the current version on both the device that made the backup and the device restoring it, then export a fresh backup and try again.

“Could not read this backup”

The file itself is not a valid backup - it is corrupted, truncated, or not a .kbk at all. The file picker does not filter by file type, so it is easy to select the wrong file by mistake (a screenshot of your passphrase, for instance, instead of the backup itself). Some messaging apps and cloud sync tools also alter files in transit; if you moved the backup through one of those, re-transfer it directly rather than through a share sheet that re-encodes it, or re-export a fresh copy.

“You already have a stack called …” or a conflicting service

This is not a corrupted backup. It means the restore would collide with something already on this device - a stack with the same name, or a service already configured under a different stack. The restore screen has two ways through this:

• Replace everything wipes your current stacks, keys, and saved certificates first, then restores the backup cleanly. This is destructive: use it only when you mean to fully replace what is on this device.
• Leave it off and the restore updates the stacks you already have and adds new ones from the backup, without removing anything. For a clean merge instead, rename or remove the colliding stack locally first.

After a successful restore

Two things do not come back automatically, on purpose:

• Certificates are re-checked against each host the next time you connect, unless you explicitly turn on the trust-saved-certificates option during the restore (it names the number of certificates in your backup). A foreign or tampered backup should never silently pin the certificates it names.
• Notifications need the Reconnect notifications option turned on during the restore to rejoin the account this backup belonged to. Without it, the stacks and keys come back but this device stays off that notification account.