Views-overriden taxonomy/term page returns not found I am trying to override the default taxonomy/term/xxx page with a page created by views.

My view: I have followed the usual instructions with using url taxonomy/term/%, gave it a contextual filter that is validated to a term name. In the preview results box of this view, I can use a term as an argument, and get the results correctly. 

But when use the url in the real site, I get a 404. Regardless what the url alias pattern is for the default taxonomy term pages, when this view is enabled no term will return a page.

Turning my view off->term page urls work 
Turning my view on ->term pages stop working.

I have no other view with the same URL enabled.
I was able to solve this only by duplicating the "taxonomy" view. This view's argument configuration makes it a viable solution. 

After configuring/enabling this view, you can set the taxonomy url aliases to work in the same way.

A working example: http://www.indice.gr/portfolio/all shows "all" projects, wheras http://www.indice.gr/portfolio/mobile-application shows projects under the mobile-application term. Yay!