Issue Upgraded from wpDiscuz 5.3.6 to 7.6.28 – An error of type E_ERROR was caused

I’ve just upgraded from wpDiscuz 5.3.6 to 7.6.28 and now getting an error when trying to complete the steps of the installation wizard.

I am selecting the comments style ‘Light’ and choosing comments layout ‘Layout #2’ and then clicking on the ‘Next Step’ button. It is at this stage that I get the error message:

“There has been a critical error on this website. Please check your site admin email inbox for instructions. If you continue to have problems, please try the support forums. Learn more about troubleshooting WordPress.”

The error logs are showing the following:

When seeking help with this issue, you may be asked for some of the following information:
WordPress version 6.7.2
Active theme: Astra Child (version 1.0.0)
Current plugin: wpDiscuz (version 7.6.28)
PHP version 8.4.4



Error Details
=============
An error of type E_ERROR was caused in line 1349 of the file /home/testsite/public_html/wp-content/plugins/wpdiscuz/options/class.WpdiscuzOptions.php. Error message: Uncaught TypeError: Cannot access offset of type string on string in /home/testsite/public_html/wp-content/plugins/wpdiscuz/options/class.WpdiscuzOptions.php:1349
Stack trace:
#0 /home/testsite/public_html/wp-includes/class-wp-hook.php(324): WpdiscuzOptions->saveAndResetOptionsAndPhrases('')
#1 /home/testsite/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#2 /home/testsite/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#3 /home/testsite/public_html/wp-admin/admin.php(175): do_action('admin_init')
#4 {main}
  thrown