SyncError:304 – Some file contents have not arrived yet

In short: SyncError 304 is often more of a status message than an actual error. SimpleumSafe already knows about the file, but its content has not yet arrived on this device. There can be normal reasons for this—usually, synchronization has not yet finished on one of the devices involved.

The device showing the message does not yet have the listed files in full. Allow synchronization to finish. Further steps are only necessary if the message appears again afterwards.

How does synchronization work?

SimpleumSafe synchronizes two parts of every file:

  1. The file information: This includes the file name, folder, size, creation date, and modification date. This small amount of information is transferred first. As a result, you may already see a file in your Safe even though its content has not yet arrived.
  2. The file content: The actual data in the file is transferred afterwards. While it is still missing, SimpleumSafe displays the file name in gray. Once the transfer is complete, the file name returns to its normal appearance.

Think of it as a table of contents arriving before the documents it lists: the list is already there, but some of the content is still in transit.

Why can this happen?

Synchronization often ended too early on the device that has the complete file. This can happen if you close the Safe, quit SimpleumSafe, or disconnect the device from the sync target before all file contents have been transferred.

On iPhone and iPad, iOS may also suspend an app shortly after it moves to the background. A synchronization that is still running may then remain incomplete. Keep SimpleumSafe open on the screen until the app reports that synchronization has finished.

Other normal reasons include a slow or interrupted connection, large files, or synchronization that has not yet been started again on the receiving device. In these cases, the message initially tells you only which part of the transfer is still pending.

Where can the transfer still be pending?

There are two possible pending routes for an affected file:

  1. From the device with the complete file to the sync target: The file content has not yet been fully provided or uploaded there.
  2. From the sync target to the device showing the message: The file content is available at the sync target but has not yet been fully retrieved or downloaded by this device.

Depending on the synchronization method you selected, the sync target may be iCloud or a folder, for example. With direct device-to-device synchronization, the data is transferred directly between the devices.

In both cases, SyncError 304 initially describes the same intermediate state: the file information has arrived, but the associated file content has not.

The same Safe on device A and device B with three files. On device B, the middle file is gray because its content has either not yet been uploaded to the sync target or not yet been downloaded.
The gray file is already known. Its content is still waiting on one of the two transfer routes.
Possible pending route
  1. Device A has not yet uploaded the file content to the sync target.
  2. Device B has not yet downloaded the file content from the sync target.
Two possible pending routes shown one above the other: either from device A to the sync target or from the sync target to device B, where the middle file is gray.
The gray file is already known. Its content is still waiting on one of the two transfer routes.
Possible pending route
  1. Device A has not yet uploaded the file content to the sync target.
  2. Device B has not yet downloaded the file content from the sync target.

How to complete synchronization

  1. First, synchronize the device named in the message.

    Open the Safe on that device and allow synchronization to finish completely. This device needs to provide the missing file content.

    Keep SimpleumSafe open on the screen during synchronization on iPhone and iPad. If you switch to another app, iOS may suspend SimpleumSafe after a short time and the transfer may remain incomplete. Wait until the app reports that synchronization has finished.

  2. Then synchronize the device that displayed SyncError 304.

    It can now retrieve the file content that has been provided. Afterwards, check whether the affected file names are still gray and whether the message appears again.

If the message still appears

Use Integrity Checker if SyncError 304 appears again after both synchronization runs. It checks the Safe for incomplete files and identifies pending transfers again:

For a general explanation of the results and available repairs, see Integrity Checker: what it checks and what the results mean.

What if the named device no longer exists?

If the device named in the message is no longer available, an outdated entry in the internal list of pending file transfers may be the cause.

Only follow these steps if the data is complete on at least one available device and Integrity Checker reports no errors or data loss. If you are unsure, contact Simpleum Support. Do not delete the Safe or its CloudKit data.

First, create a current backup and make sure that no other device is currently synchronizing this Safe. Then follow these steps on your Mac:

  1. Open the Safe. If you are asked whether to resume an earlier backup, choose Cancel.
  2. Open Help > Safe Doctor.
  3. Select Sync STFL. STFL is the internal list of pending file transfers.
  4. Select Delete all STFL entries and confirm the action.
  5. Start synchronization again, then run the integrity check including the synchronization check.

If SyncError 304 appears again, contact Simpleum Support. Include your SimpleumSafe version, operating system, the device named in the message, and the Integrity Checker result. Never send your password or recovery key.