The mbstring PHP extension was not found and you seem to be using a multibyte charset. Without the mbstring extension phpMyAdmin is unable to split strings correctly and it may result in unexpected results.
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i enabled utf8mb4 connection to mysql as i need characters of other language and got the error. the website is down…
Regarding your website being down, that’s probably because of this issue:
The mbstring extension is enabled on all websites (or at least, it should be), and the extension being missing is not usually the issue.
I checked your database in phpMyAdmin as well, and I can see the Bengali characters being rendered correctly there, so I don’t see any inherent issues with handling multibyte strings on our end.