LAGIQQ » Could you please explain what does error code 404 mean ?

Use the tools described below to determine what does error code 404 mean in WordPress. Begin by rebuilding the permalinks on your WordPress website. From your WordPress dashboard, go to Permalinks > Settings. choose Save Changes. It's OK if you don't alter any setting changes post this step. Even if no modifications are made, the permalink settings will be updated. This is significant since it alters the conditions for rewriting "permalinks."