PHP 8 Fatal error

We got fatal error on updating to PHP 8.1
WordPress version: 6.1.1
PHP version: 8.1

Error message:

Got error ‘PHP message: PHP Fatal error: Uncaught mysqli_sql_exception: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘IF’ at line 1 in ……/frontend/wp-content/db.php:1201\nStack trace:\n#0 ……/frontend/wp-content/db.php(1201): mysqli_query()\n#1 ……/frontend/wp-content/db.php(838): hyperdb->ex_mysql_query()\n#2 ……/frontend/wp/wp-includes/class-wpdb.php(2854): hyperdb->query()\n#3 ……/frontend/wp/wp-admin/includes/upgrade.php(2792): wpdb->get_results()\n#4 ……/frontend/wp-content/plugins/wp-maintenance-mode/includes/classes/wp-maintenance-mode.php(412): dbDelta()\n#5 ……/frontend/wp-content/plugins/wp-maintenance-mode/includ…’,

Hi @artiomrudenco,

Thanks for choosing Visualizer!

I checked this on my test instance and I don’t get any error with PHP8 or PHP8.1. Where does this error appear for you? Also, the second error you shared doesn’t refer to Visualizer, but to a different plugin. You could try to deactivate the rest of the plugins while keeping Visualizer active and seeing if the issue persists.

Have a nice day!

@luciamarinescu
We found broken chart in Admin -> Visualizer -> Chart Library.
This chart has red label:
“All series on a given axis must be of the same data type“
Database -> there is no meta_value (empty string) for meta_key = ‘visualizer-settings’ on related post.

Looks like when user broke charts it broke related posts (parent/child) on FE.

@luciamarinescu
Hi Lucia,
I see one more error (maybe it could help you):

AH01071: Got error ‘PHP message: PHP Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /…./frontend/wp-content/plugins/visualizer/classes/Visualizer/Render.php:92

\nStack trace:
\n#0 /…./frontend/wp-content/plugins/visualizer/classes/Visualizer/Module/Chart.php(836): Visualizer_Render->__set()
\n#1 /…./frontend/wp-content/plugins/visualizer/classes/Visualizer/Module/Chart.php(697): Visualizer_Module_Chart->_handleDataAndSettingsPage()
\n#2 /…./frontend/wp/wp-includes/class-wp-hook.php(308): Visualizer_Module_Chart->renderChartPages()
\n#3 /…./frontend/wp/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters()
\n#4 /…./frontend/wp/wp-includes/plugin.php(517): WP_Hook->do_action()
\n#5 /…./fro…’, referer https:///wp-admin/admin.php?page=visualizer&vpage=3

Hi @artiomrudenco,

Thank you for sharing more details. We haven’t received similar reports since so it looks like an edge case with a specific chart that you created.

Do you still get this error? Maybe you could share details about that chart that brought this fatal error? What was the chart type what were the settings or data used as a source so we could try creating such a chart to replicate the error.