When renewing Joomla 3.8.7 to 3.8.8.
I get the following error message on the website.
The administrator side is still accessible.

Error: 0 - Using $this when not in object context

You may not be able to visit this page because of:

an out-of-date bookmark/favourite
a search engine that has an out-of-date listing for this site
a mistyped address
you have no access to this page
The requested resource was not found.
An error has occurred while processing your request.

The php version is 7.1

The problem is the random image of Joomla

This is the problem in default.php
<?php echo JHtml::_('image', $image->folder . '/' . $this->escape($image->name), $this->escape($image->name), array('width' => $image->width, 'height' => $image->height)); ?>

This is the good one:
<?php echo JHtml::_('image', $image->folder . '/' . $image->name, $image->name, array('width' => $image->width, 'height' => $image->height)); ?>

Here can you find it default.php
modules\mod_random_image\tmpl\default.php