Also took me hours to fix several of our websites, these essential changes came extremely unexpected. There should have been a prominent notice in the backend for the latest 2-3 versions, that there are fields/functions in use, that could cause issues with the upcoming version.
Apart from that: If you are facing serious issues that have impact on your site/rankings, I would recommend to download a previous version of this plugin on your account page and then implement all needed fixes in another dev environment without hurry and testing everything, before doing the final switch on the live site
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