Child themes not working

I’ve followed the video tutorial to install the child theme of ‘Healthy lifestyle’, and compressed the folder into a .zip file (as with all the parent themes, since there’s no .zip file in the download, which can be a bit confusing too, when you tell people to just upload the zip file), and uploaded it, wanting to use it with the parent theme of Directory (which should be fine). Thing is, it does not work, telling me that I have to install the right parent theme first (which is in place). Then I thought it might have to do with updating the PremiumPress themes, so I pressed the ‘update’ button, just to be let known that it caused an error and it couldn’t be updated. So now all i have on my site is a white screen saying ‘down for maintenance’ (in Danish).

Thanks!