Hello

Thank you for your query. If you want to update SP Page builder, could you download and install the updated version manually from the link below:

https://www.joomshaper.com/downloads/extension/sp-page-builder-pro

You can follow our documentation as well for more information:

https://www.joomshaper.com/documentation/sp-page-builder/sp-page-builder-3/installation

I don't want to update the page builder. The question was an upgrade to joomla 4. I think the question is understandable.

My apologies. You can update to Joomla 4 even if you see any warnings for SPPB system plugins from Joomla Tester - you can ignore them and follow the upgrade steps. Of course, we recommend doing a full backup before.

I read the recommendation joomshaper. But after i upgrade the site from 3.10 to 4.0 I get the error Class 'JString' not found instead of the control panel or system panel.