Unknown column 'n.id' in 'on clause'

Query:
SELECT n.id,n.datetime,c.name as category,n.numviews,n.subject,n.text,n.quote,n.link,n.sourcename,a.name,a.email,count(t.threadid) as numthreads FROM news n,news_categories c,authors a LEFT JOIN threads as t ON n.id=t.headline WHERE n.author=a.authorid AND n.status=2 AND n.category=c.id GROUP BY n.id ORDER BY n.showorder DESC,n.datetime DESC LIMIT 10

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