[Solved] Printful Sync Error – HTTP Error 414 Request-URI Too Long

Problem: Printful.com shop is displaying the following syncing error message: Something went wrong with sync. Received error: HTTP Error 414 Request-URI Too Long. Try to refresh data. Solution:¬†Adjusted a setting in the WordPress iThemes Security plugin: WordPress admin > Security > Settings > System Tweaks > un-tick the “Filter Long URL Strings” setting