Attempt URL alias for spanish version of page - "The path */* is either invalid or you do not have access to it." Drupal 7.59. We have the page whatever.tld/thanks and whatever.tld/es/thanks.
I'm trying to setup whatver.tlp/gracias as a URL alias for es/thanks and it says "The path 'es/thanks' is either invalid or you do not have access to it."

The page itself is a tpl.php file referred to by a view and has individual blocks on it that are translated.

This translation stuff is beyond me. I have a dev site to practice on so I'm happy to try out any ideas. The following (apparently) applicable modules are enabled:


GTranslate
Block languages
Internationalization
Menu translation
Multilingual content
String translation
Translation sets
As @prkos mentioned enable the languages module. In the Configuration/Regional and language/Languages settings you select the code you wish to use for your languages. The choice is obviously yours but when I have a multilingual site I prefer to use the ISO language code to help define the languages on the site.