mot de passe mysql localhost (Pas de réponses)

Bonjour
ce matin je ne peux plus me connecter a phpmyadmin localhost a mysql
wampserver 64 bits 3.2.0
mysql 8.0.18
je recois les erreurs
1-Impossible de se connecter au serveur MySQL
2-mysqli_real_connect(): Server sent charset (255) unknown to the client. Please, report to the developers
3-mysqli_real_connect(): (HY000/2054): Server sent charset unknown to the client. Please, report to the developers
Je n'avais pas modifié root sans mot de passe
lorsque je lance index.php
4-Notice: Undefined index: txtProjects in C:\wamp64\www\index.php on line 360
lorsque je lance un programme faisant appel a mysql connect
5-mysqli_connect(): Server sent charset (255) unknown to the client. Please, report to the developers in C:\wamp64\www\amen\outils\classeJR.php on line 332
6-mysqli_connect(): (HY000/2054): Server sent charset unknown to the client. Please, report to the developers in C:\wamp64\www\amen\outils\classeJR.php on line 332
que me conseillez vous de faire
merci
Jacky