Warning: call_user_func_array on WP

Is this plugin not viable on WordPress V. 6.1?
I get this error when activated:

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘RGForms::maybe_process_form’ was given in /home/econet/public_html/wp-includes/plugin.php on line 406

Is there a fix? This plugin is important to our world, so warrants being updated, and the developers credited enough to warrant it.

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