OK, now you are making sense. But no, MySQL 5.7 has nothing to do with it. Also, your problem was with the restoration which is
irrelevant to the version of Akeeba Backup you have installed.
Your problem was that you had an old table in utf8 collation whereas your site is using the utf8mb4 collation. To cut a long story short the solution is to deselect (clear the checkboxes of) the options Force UTF-8 collation on database and Force UTF-8 collation on tables
in the restoration's Database Restoration page. Note that these are not selected by default.
So of course this issue won't happen again when you upgrade Akeeba Backup since the problem stemmed from you checking two optional boxes in the Database Restoration page and the issue had to do with the data you had backed up :)
And that's why we ask for exact error messages. It would have saved us more than an hour of wasted time between us and you'd have gotten a reply much easier. Please, don't give us your misinterpretation of the situation as facts. You did NOT see an error message telling you to upgrade MySQL. By claiming that falsehood as a matter of fact you are derailing our troubleshooting process. Again, that's why we ask for exact error messages; it prevents wild goose chases (I had to read every. single. message you could have possibly seen and audit the installation and restoration code for MySQL version checks - that's a full hour I spent this morning before replying to you). Thanks.
Nicholas K. Dionysopoulos
Lead Developer and Director
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