Not able to post new page or post

Hello,
I am not able to post new page or post. The pages are using Site Origin Page Builder.
I contacted the theme maker of the theme and he suggested that i contact you as the error seems to stem from your plugin. See error below that i received in email. I have since updated the theme. The makeer of the theme also stated that it is your plugin that is the probelem.
Please advise on how I can fix this?

Since WordPress 5.2 there is a built-in feature that detects when a plugin or theme causes a fatal error on your site, and notifies you with this automated email.

In this case, WordPress caught an error with one of your plugins, Page Builder by SiteOrigin.

First, visit your website (https://www.radiation.org/) and check for any visible issues. Next, visit the page where the error was caught (https://www.radiation.org/wp-admin/post-new.php) and check for any visible issues.

Please contact your host for assistance with investigating this issue further.

If your site appears broken and you can’t access your dashboard normally, WordPress now has a special “recovery mode”. This lets you safely login to your dashboard and investigate further.

https://www.radiation.org/wp-login.php?action=enter_recovery_mode&rm_token=30GZDwSyyEt5F7F7C8Mp7A&rm_key=6Bne8HijmM2dtHR93GtGCb

To keep your site safe, this link will expire in 1 day. Don’t worry about that, though: a new link will be emailed to you if the error occurs again after it expires.

When seeking help with this issue, you may be asked for some of the following information:

WordPress version 5.6.1

Current theme: Gaea Child Theme (version 1.0)

Current plugin: Page Builder by SiteOrigin (version 2.11.8)

PHP version 7.4.11