Sparkle 3 - Blog not displaying correctly

Hello everyone!

I bought the upgrade to Sparkle 3 yesterday (am still on Catalina though) and have been playing with the blog-feature a bit. It all works and looks great as long as I’m still in Sparkle, but after I published the site the blog looks completely broken. I’ve not had any publishing errors before with my site ( so this surprises me a bit. See attached photos of how it looks. Anybody have and idea of what could be wrong? Cheers, Anders in Stockholm

All OK.

This stems from having renamed the blog filename from .php to .html. It needs to be .php.