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Issue 356851 – Membership: data loss Show all…

Type: Problem
State: Completed
Severity: Major
Priority: Medium
Description:

Several staff, including the reporter of this issue, have witnessed data loss when making changes to the membership spreadsheet.

More specifically, data changes are being lost, and data reversions are being observed.

Symptoms (anecdotal)
  1. A person downloads the latest membership workbook from Dropbox.
  2. They make changes to their local copy, such as adding new members, editing existing ones, "removing"† old ones.
  3. The edited workbook is uploaded to Dropbox‡.
  4. The workbook is later examined*. The recent changes have been lost#.

Notes:

† Note that we don't tend to remove rows in the sheets, but mark them as "deleted", e.g. by setting the type to "xGroup".
‡ A new name for the Excel file may be used, but this has not been made clear.
* Whether another local copy is taken, or whether the data are viewed directly via Dropbox's interface, is not known.
# Whether this is a reversion to the exact previous state, or whether a different set of changes has replaced the new ones, is not known.
Resolution:

At the point of this issue being reported, it was unclear whether:

  • Software problems are to blame,
  • Human error is involved,
  • Both.

As there's a lack of concrete evidence, at least none that can be witnessed in a reproducible way, please report any instances, stating where possible:

  • The exact steps you took,
  • What you expected to happen,
  • What actually happened.
Theory

One possible theory is that these problems occur when more than one person is making changes during the same approximate period of time.

Essentially a "leap frog" issue, due to the timing of the steps taken, as hopefully the diagram below demonstrates.

Image: Diagram showing how data loss can occur when two people edit the membership data

As yet, there is no proof nor disproof of this, so it remains a working theory.

[31-Mar-2026 Kevin] We've discovered that there are problems with using the Dropbox built-in spreadsheet viewer/editor. Among other possible issues are:

  • Viewing counts as editing, leading to unnecessary file revisions.
  • Changing the filters causes edits to be made.
  • "Empty" rows are added, causing the file size to increase massively, e.g. from ~200 KB to ~3 MB.
  • Due to the above, the risk of concurrent editing is greatly increased, merely by looking at the file.

[22-Jun-2026 Kevin] Further incidental evidence has pretty much proved that concurrent overlapping edits are by far the biggest problem.

This is a human problem, not a technical one. The fact that the technology permits these actions could be eventually improved upon, but that can be tracked as a separate issue.

This issue is now marked as completed, since recommendations have been made to circumvent concurrent overlapping edits.

Reported by: Liz Ashcroft
Assigned to: Kevin Machin

Author: Kevin Machin ♦ Created: 24-Feb-2026 ♦ Access: public ♦ Issue: membership-data-loss