Hello Kenzie,
Sorry to hear the Post and Page Builder was causing a fatal error. We recently updated our plugins for better compatibility with the WordPress Core 5.6 release and have not noticed any fatal errors with the most recent version. Please ensure all your plugins, themes, and WordPress itself are on the most recent versions.
If everything is up to date and you encounter any more fatal errors when activating the plugin we would appreciate it if you could send us the full error message so our development team can investigate any additional compatibility issues.
Thanks,
Nicole