I found https://community.nodebb.org/topic/10026/nodebb-plugin-write-api-failing-to-load-admin-page solving the issue.
Hosted NodeBB: Did you change the hosting plans?
Actually, I wanted to ask some different question about your hosting solution, but now I see that you have changed the hosting plans and pricing.
It starts now from 100$/Month
So you don't have cheaper plans right now?
We've recently raised our prices to reflect our new pricing plans for NodeBBs going forward. The new plans differ from the old in that they all offer daily on-disk backups, and support a higher number of users. Additionally, all plans will benefit from real-time monitoring so that in the event a forum goes down for whatever reason, somebody from our team will be on-hand to resolve the issue without you having to open a support ticket.
In the event we change prices again in the future, please be advised that existing NodeBBs will continue onwards with the existing monthly price.
Again, this pricing change does not affect existing customers of the hosted service
Do you use CDN for customers outside USA/Canada for faster content delivery?
@prog At current, no. Our servers are based in a New York datacenter, but we do not use CDN for global delivery of assets like the client js and css.