Hello JoomShaper team,

since updating to 6.9.x the backend editor no longer opens pages that were created in older versions and never re-saved. The editor shows an endless loading spinner.

Environment: Joomla 6.1.4, SP Page Builder Pro 6.9.1, site migrated from Joomla 3. 658 of our 791 pages still have their content only in the legacy text column; the content column is empty.

What happens

1. Open a legacy page in the backend editor (administrator/index.php?option=com_sppagebuilder#/editor/<id>/).
2. The request task=/editor.pageContentById&id=<id> returns HTTP 200, but with "text": null.
3. The editor then throws "TypeError: Cannot read properties of null (reading 'map')" in assets/editor/dist/js/bundle.min.js and the spinner never goes away.

The same pages open and work in the frontend editor. Pages that were saved once with 6.8.0 (their content is filled) still open fine in the backend.

Expected: the backend editor should convert legacy text content on load, as the older 6.8.x did, or at least show an error instead of a spinner.

Questions: Is this a regression in 6.9.x? Is there a migration tool for pages from older versions? Is there a way to bulk-convert legacy pages?

Thank you!