In your bot's edit, http://pcgamingwiki.com/w/index.php?title=Mass_Effect_3&diff=259422&oldid=255488 , it inserted |ref={{cn|{{subst:DATE}}}} instead of |ref={{cn|date=July 2016}}.
Not sure if this is caused by your bot or mediawiki.
Topic on User talk:Garrett
That example is inside a comment (it seems MediaWiki doesn't process comment substitutions). The other dates in that edit were generated with the same substitution code.