Inspect first, migrate second
For many users, the first THS contains years of field history. The migration therefore starts with a preview rather than an immediate database write: the app shows the source database version and the number of trips, GPS points, findings, types, photos and KML sets it found.
Empty or damaged photos do not abort the whole migration. THS2 reports them, skips the affected files and continues with the remaining data.
Running it again does not create duplicates
The importer adds only missing records and does not replace data already created in THS2. This makes it safe to retry after repairing a source backup or restoring missing files.
When the process finishes, the app reports what was migrated, what was skipped and why. The original backup remains unchanged, so it can still be kept separately.