Discourse theme error after update?

Hoping somebody can help as I’m running out of options!

I upgraded my clients discourse running off a digital ocean droplet. Now we appear to have lost the theme completely, I can access the console and I presume content is still there as all the URLs link through to pages but literally no visible display - https://iartaforum.com

inspect shows the error - “discourse could not find module discourse/lib/theme-settings-store”

If anyone can offer any advice, I’d be extremely grateful!