Something wrong with your database setup. It seems your WordPress doesn't have access to MySQL's information_schema.tables. This is an unusual issue.

In any case, I just updated the script. It should work in your case as well. Please delete the previous script. Again, make sure it's deleted, then copy and use the new script.

That's just impossible. Are you testing on a live website? The code has been tested on 5 different hostings and on localhost, it works fine. Please make sure you've copied and pasted the source code correctly, leave some screenshots.

The name of the forum and the name of the section, can I make them abbreviated to be for example with out the subforum

I'm sorry, but there is no way to do a structural change in URL.

I've just updated the code, please copy again and replace the old one in your website.

Thank you very much. It works. I really appreciate this 😍 

Is there a way to shorten the name of the forum, for example?

example.com/forum/experience/1

domain / forumname / subforum / postID

The name of the forum and the name of the section, can I make them abbreviated to be for example with out the subforum

example.com/forum/1

You can set the topic ID as the topic slug using hook code.

Put this code in a PHP snippet using Code Snippets plugin or in the functions.php file of your current active WordPress theme:

add_filter('wpforo_add_topic_data_filter', function( $args ){
    if( wpfval($args, 'slug') ){
        $topicid = WPF()->db->get_var("SELECT MAX(`topicid`) as topicid FROM `" . esc_sql( WPF()->tables->topics ) . "`");
        if( $topicid ){
            $args = (string) ( intval($topicid) + 1 );
        }
    }
    return $args;
}, 10);