I'm getting the same structured data error on search console form most of my websites, Invalid value in field "itemtype" I take off all the structured data but still having this problem, according to Search console is a syntax problem but I can't find what is causing this. Any guess, suggestion or solution for this?

Hi there, we've noticed a sudden drop in both trust and citation flow scores for many of our clients' websites. We haven't done any black hat activities nor done anything differently the last few months that we can think have contributed to this. We have however noticed a backlink from a website: http://www.wordsmith.org/awad/archives.html that has appeared across all the websites which have dropped in rankings. Could this link be the contributing factor & would that mean someone has linked it to our clients' websites?