It seems there are portions of the content which is just a bunch of symbols, at least that's what the results are showing (ie. "±ÆÆßÚ ÔÏ œ ‹± ß±´ Wø™ª ø7ß ÆªøT±7 ¨± 檥1ª™ª ¨Wø¨ ø7ß ÔÎ ±J ß±´Æ \Æ1±Æ ")

If I click the associated PDF document, I can see there is legible text, so I think it might be an issue with the ingestion of the document itself.