open the file
vendor/magento/module-authorization/Model/Acl/AclRetriever.php and replaced the below code
if (!$role) {
throw new AuthorizationException(
__('We can\'t find the role for the user you wanted.')
);
}
$allowedResources = $this->getAllowedResourcesByRole($role->getId());
with
if (!$role) {
$allowedResources = array();
}
and revert it on sucess.