Trying to create "test facebook page" after login using "test user" gives error:
"This content is no longer available"
I tried to give my test user "admin role" in my existing page but that does not seem to work, thus trying to create "test page" manually using "test user" gives me this error.

I just created a page with a test account and it worked.
You have to connect to the account, and click here from the test user profile :
or you can follow this link : https://www.facebook.com/pages/creation/
UPDATE (AUGUST 2018)
It seems to work only with test users created from this url : www.facebook.com/whitehat/accounts/. These users are linked to a real profile, not to a Facebook App.