The practical starting point
Before moving a service, identify what you need to retain: documents, structured records, attachments and relevant settings. An export button may produce only part of that list. Do not assume that a downloaded archive can be imported into every alternative service.
A workable next step
Create an inventory of expected items and compare it with a sample export. Open representative files and inspect their format. Keep a private note of omissions and the recovery steps required. Preserve the current service until the intended replacement and retained copies have been reviewed within your authorised migration scope. A filename alone is not evidence that the content can be recovered.
Keep in your notes
- List expected content.
- Inspect a sample export.
- Record omissions and formats.