RSS feed is not work

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Search Resultlist RSS feed is not available sometimes, mistakes like this

[0] A feed could not be found at https://patentscope.wipo.int/search/rss.jsf?query=PA%3A%E5%90%8C%E7%A8%8B%E7%BD%91+&office=&rss=true&sortOption=Pub+Date+Desc. A feed with an invalid mime type may fall victim to this error, or SimplePie was unable to auto-discover it.. Use force_feed() if you are certain this URL is a real feed.

often turn out.