Error after changing the database character set to utf8mb4

[metrprime (Easton)]

check this buddy, end of the thread it’s a potential solution:

Your database does not support utf8mb4

Hi, https://mathiasbynens.be/notes/mysql-utf8mb4 claims that MySQL 5.5.3 is the first version supporting utf8mb4. But of course it might be possible that whoever compiled your binary disable the feature at compile time.