Custom taxonomy page returns 404

but it returns a 404 when I go to mydomain.com/mycustomtaxonomy

The problem is that you’re expecting behavior that simply doesn’t exist. Just like mysite.com/category will 404, so will mysite.com/mycustomtaxonomy

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)