Error in moxiemanager with PHP7

After updating the version from PHP5 to PHP7, an error appears when trying to insert images from the moxiemanager plugin of the tinymce that I have integrated into the project.

just tell me: Error: Array to string conversion

After a few hours, I could find the error

Specifically in: /home/user/website/admin/js/vendor/tinymce/plugins/moxiemanager/classes/Util/EventDispatcher.php:118

In the method:

public function dispatch($sender, $name, $args) {
    $name = strtolower($name);

    if (isset($this->observers[$name])) {
        $observers = $this->observers[$name];
        $args->setSender($sender);

        for ($i = 0, $l = count($observers); $i < $l; $i++) {
            $value = $observers[$i][1]->$observers[$i][0]($args);

            // Is stopped then break the loop
            if ($value === false || $args->isStopped()) {
                return $args;
            }
        }
    }

    return $args;
}

you must replace the following line:

$value = $observers[$i][1]->$observers[$i][0]($args);

For this:

$value = $observers[$i][1]->{$observers[$i][0]}($args);

PHP7 uses an abstract syntactic tree when analyzing the source files. Indirect access to variables, properties and methods will now be strictly evaluated from left to right.