The character set & # 39; utf8mb4 & # 39; it is not a compiled character set and is not specified in the file & # 39; /usr/share/mysql/charsets/Index.xml'

Complete error

The character set & # 39; utf8mb4 & # 39; it is not a compiled character set and is not specified in the file & # 39; /usr/share/mysql/charsets/Index.xml'
InvalidArgumentException: There was a problem connecting to the database: SQLSTATE[HY000] [2019]    Unable to initialize the utf8mb4 character set (path: / usr / share / mysql / charsets /)

mysql See 14.14 Distrib 5.7.26

I'm trying to fix this error, but I can not fix it on an active server. I had to go through the procedure of adding the following to the /usr/share/mysql/charsets/Index.xml file in a local virtual machine that worked.


  Unicode
  UTF-8 MB4 Unicode
  
    primary
    compiled
  
  
    binary
    compiled
  

I have restarted mysql a couple of times since I updated this in vain. My database connection is shown as such

<? php
$ db = new PDO ("mysql: host = $ host; dbname = $ db; charset = utf8mb4", $ db_username, $ db_pass);

And all the variables in my database seem to be verified based on other publications I've seen

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my.cnf has the following set also

set of characters-server = utf8mb4
collation-server = utf8mb4_unicode_ci