When saving a marker I get the error “a marker with the ID 0 does not exist!”

This FAQ is only valid for Maps Marker Pro v3.1.1 or lower:

Please check if the database tables needed for Maps Marker Pro have been created by logging into your database tool (usually phpmyadmin) and checking if the tables

• wp_leafletmapsmarker_markers and
• wp_leafletmapsmarker_layers

exist. If yes, please turn on WordPress debugging (by adding define(‘WP_DEBUG’, true); to wp-config.php), also have a look into the PHP error log if possible and open a support ticket with the logged results.