This type of issue is not found on our demo and we checked our site and it is working fine. It may cause the error due to plugin, upload permission issues or may be due to server issues. If we got that issue we will inform you because we haven’t got such types of issue here. And while viewing your site there are lots of issue on the site console, it may arise due to change in theme edit or plugin conflicts.
Please remove unwanted plugins and check it.