Unexpected HTTP response: 500

Request
{
    "users-properties" => {
        "path" => "mgmt-users.properties",
        "relative-to" => "jboss.server.config.dir"
    },
    "groups-properties" => {},
    "address" => [
        ("subsystem" => "elytron"),
        ("properties-realm" => "test")
    ],
    "operation" => "add"
}

Response

Internal Server Error
{
    "outcome" => "failed",
    "failure-description" => "WFLYCTL0155: 'path' may not be null",
    "rolled-back" => true
}