When updating SP Property from 4.04 to V4.1.1, the following error occurs:

Call to undefined method Joomla\CMS\Document\HtmlDocument::getWebAssetManager()

I have updated Helix3, the template (Empire). I can't find the error.

But I have the following idea: I don't have to change the page from J3 to J4 (or J5), I would like to set up a new template based on HelixUltimative. Is there a tip on how I can get the SP Property data (locations) into the new installation?

Then I'll save myself the long trial and error search and do everything again.

Best regards Kay