Rewrite results (like trimming titles) won't work at all I created a view with articles. All I need is to trim titles.
The reason I cannot do this from content types (teaser view) is because the title field is a node module element. (It cannot be deleted, and is too late for that.)

There is an option in views output in the preview mode/contextual menus/rewrite results, but it seems it won't work. 



None of the rewrite results options will work. It looks like a bug in the Views module.
Clear your Drupal cache by visiting /admin/config/development/performance or if you use the Drush module, simply run drush cc all

Also make sure you're editing and viewing the correct view.  If you're modify the master display but viewing an overwritten display, your master view settings will have no effect.