The website https://akb-zwartewaal.nl was broken after the latest Cornerstone update from 5.0.10 to 5.1.5.
I have already restored the site from a backup to put the plugin back to 5.0.10
To show you what went wrong I have enclosed a screen dump of the broken website after the update to 5.1.5.
How can I update to the newest version of Cornerstone?