As no one has answered this post, I thought I might add to it. I too have the same problem.
In the user guide multi lingual section, appears,
“The multilingual settings makes it easy to create and manage separate page tree structures for each language. Each language — even the language your site is currently written in — will get its own parent page, under Concrete CMS’s default “Home” page.”
I followed the instructions and set up the second language. In the page report tab in the system and settings, multi lingual section I get at the first page of the second language with “Create the parent page first.”
Indeed at the bottom of the user guide multi lingual section there is included a screen shot of the page report tab which shows “Create the parent page first.” at the top of the tree of the second language. As far as I can see in the user guide multi lingual section there is no description of how to make the first page become the parent page.
It seems a little bit strange.
In the website as I have set it up, the language switcher and both menu trees seems to work fine, even though I do not have a parent page in the second language.
Is this parent page only necessary when using the page mapping and translation facilities?
I just need 2 menu trees and a language switcher I intend to build each language tree separately and do the translation manually.
If I remember well there is a bug listed in Github about the behavior of the site logo and tile which redirects back to home page whichever language you start from. Is this something to do with no parent page?
note,
it appears there are 2 different pages in the user guide concerning setting up a multilingual site
It does make life confusing for a new comer. Perhaps one of the links is to legacy docs, but there no indications if this so or not, No dates either.