Form DB error

Hello,

I am using the Elementor Pro version and I am trying to create a form.

In the Elementor training video its has been explained how to add a Form DB for the from created on ePro. The recommended plugin on the video is Lenix Elementor Leads addon.

After adding the plugin I get the following error

Warning: Parameter 2 to modify_where_for_old_leads_vaersions() expected to be a reference, value given in /home2/user/public_html/wp-includes/class-wp-hook.php on line 286

Also the following error shows up in the middle of the screen

Thank you for creating with WordPress. Version 4.9.4

Why am I getting these errors? Is your plugin compatible with OceanWP 1.5.4 theme?