=== Upgrading from MirrorSync version 4 and 5 ===
MirrorSync 6 is backwards compatible with version 4 and 5 offline files. That means that you can safely install this update over your existing MirrorSync installation. Immediately after the update finishes, syncs with older configurations will not work - use the MirrorSync configuration client to edit the older configurations. Once you've edited the configuration and your changes have been saved, your offline users will still be able to sync. You do not need to reset sync data or delete / recreate configurations. The license key will also remain the same, since MirrorSync is licensed on a maintenance model.

Many of the new features in MirrorSync 6, such as streaming record transfers, require a new offline file with the MirrorSync 6 script. For this reason, we recommend that after your clients have completed a sync with the older file, you distribute a new offline file to them with the new MirrorSync 6 script. You can do this manually, but the way we recommend is by changing the DatabaseVersion field in the MirrorSync table. This will trigger an automatic update operation after their next successful sync. It will work OK to have some clients syncing with older (4 and 5) MirrorSync scripts, while other clients are using the new MirrorSync 6 script.

=== Upgrade from MirrorSync version 1, 2, or 3 ===

MirrorSync 6 is not compatible with configurations or offline files older than version 4. Before running this update, ensure that all users with version 3.x offline files have synced all of their changes to the server. Then distribute new offline files after completing the update.