When a username has an ' in it (I suspect, the username I encounter has an ' and whitespace following it.) it breaks the query.
For example, The username Ol' Willy gets reduced to just Ol, breaking the query, resulting in a query like "contoso.com/plexWatch/user.php?user=Ol"
Correcting the string in the URL results in "Failed to access plexWatch database. Please check your settings."