[WPMU DEV Dashboard] Elementor landing page crashes site

Hi guys
I’ve signed up for the Elementor Pro package, so I can easily create landing pages on my site.
To create a standalone web page, I set the page settings to Elementor Canvas, import a template and publish it. On my digitalscot.net site this then displays no problems.
But when I repeat exactly the same approach on biggar.online, it crashes the site when you try and display it, see:
Any ideas?
I’ve enabled Support Access. This is a mapped domain subsite of digitalvillage.scot.
Cheers, Neil.