SyncError:304 - Not all files received from the sync target/cloud

What does the error “SyncError:304” mean?

The “SyncError:304 - Not all files were received from sync destination/cloud” error occurs when not all files are successfully downloaded when syncing your files. This error indicates that some files still need to be uploaded from other devices. The error message also indicates how many files are missing and which device they should have come from.

Why is this happening?

Synchronizing your files takes place in two steps:

  1. Metadata synchronization: First, information such as file name, size, creation date and modification date are synchronized. Therefore, you may already be able to see file names and folder structures even though the actual file contents have not yet been transferred. This is particularly the case with slow connections or the synchronization of large amounts of data. The affected file names are displayed in gray during this phase.

  2. Synchronization of file contents: In the second step, the contents of the files are transferred. Once this step is complete, the file names will be displayed in black to signal the completion of the transfer.


To fix the error, do the following:

  1. Initiate sync on the device that will upload the files Make sure the synchronization is completed on this device.

  2. Resync on the device that showed the error After all files have been uploaded successfully, restart the synchronization on the other device. This should solve the problem and all files should now be fully synced.

Still not uploaded all files?

If after following the above steps you find that all files are still not uploaded from the affected device, it is necessary to use Integrity Checker. Integrity Checker helps identify and resolve file synchronization issues by re-identifying outstanding files. How to use the Integrity Checker:

Important note: Synchronization, especially via iCloud, is outside SimpleumSafe’s direct control. Therefore, there may be delays due to iCloud sync speed.

If you need further assistance or have any questions, please contact our support. We are here to help you!