Warning: Undefined array key “capabilities” in class-wp-roles.php

hello
I’m pretty new
I have this warning :
Warning: Undefined array key “capabilities” in C:\xampp\htdocs\adm\wp-includes\class-wp-roles.php on line 290

version WordPress 5.6–it_IT
plugin :

“Events Manager” Versione 5.9.8.1
“Import and export users and customers” Versione 1.17.1

the warning apper after change same parameter of “event manager” plugin
i have try deactivate all plugins, but the warning still
can i disable this warning?
i have search this key in my database and it’s very long text..

thanks
Lorenz