Hello

The issue you are facing might happen because of a few reasons:

1. Your server may have set too sensitive security level set, or
2. PHP file_get_contents() function has been disabled/locked

in that case, please contact with hosting support.

** In most cases can be changed in php.ini or .htaccess file or ask Hosting support.

Check also below settings:

1. Turn on the allow_url_fopen from your hosting
2. Check the console error using inspect element from your browser
3. Turn off the rocket loader, if you use the SSL certificate
4. Go to the file location and check the com_sppagebuilder exist or not. If exist delete the folder. templates/your_template/HTML/com_sppagebuilder
5. Turn off the mod_security from your hosting server.

You can check Chrome too, there might be a blocker plugin, that might cause the sections not to load.