Build mode 'freezes' when adding a spacer


I’m having a critical problem in Creator. When I add a spacer (at least this has happened twice after adding one) to a page in my app, the build mode in that particular page freezes so that I can’t scroll it (I can change the content in the page thought). The view mode is working fine, and so are all the other pages in build mode. The scrolling in the page is obviously enabled.

I have tried to delete cookies, restart the browser (I use Chrome on Mac) and tried in a different browser. The only thing that I’ve been able to do is to create a whole new page and copy all the content from the old page. I have so much content on the page that this is very annoying.

UPDATE: I found out the problem! I had

.scroll-content {
  overflow: visible !important;

in my SCSS because I have a transparent header. Removing this made the page work normally.