Hi,
we have a problem after updating SP Page Builder to version 5 (5.3.4) from 3.
After the update the component seems to work well with existing and completely new items. But if you open an existing article and “Save as copy”, when you open the Page Builder the error message that is in the image appears. 
We noticed that if we reinstall the previous version (5.3.3) the newly "cloned" article opens correctly, but if we "Save as copy" again the error in the image above appears again.
We have seen that there are many reports about it and we have followed the instructions you have placed at this link (https://www.joomshaper.com/documentation/sp-page-builder/troubleshooting), but it does not definitively solve the problem.
We need your help to resolve the problem permanently.
Thanks

