Two Error Messages : Fatal error: Initial Taxonomies; and

Hi,

We are experiencing two errors with our WordPress sites and welcome all advice.

For one project site called “Symptom 10,” site visitors encounter this message:
Fatal error: Call to undefined function create_initial_taxonomies() in /home/lacan/www/www/thesymptom/wp-settings.php on line 206
This is an older project (from 2009), and we cannot currently locate the WordPress log in information for this site, which makes things a bit more complicated.

Then, for several other project sites, including one called “Symptom 11,” the site appears functional to site visitors, but when we try to log in we encounter either this message:
Unauthorized
This server could not verify that you are authorized to access the document requested. Either you supplied the wrong credentials (e.g., bad password), or your browser doesn’t understand how to supply the credentials required.

Or, we encounter an “Internal error 500” message.

Please advise!