Okay, so I’ve figured this out and it seems like it’s all quite buggy.
I deleted that whole tab and re-created it. Each tab starts with a text block but does not include the option to add another text block or content element. So, I delete the existing text block and that option appears. After I added a few tabs and deleted the last text block, I got a black window like it’s in the process of adding something but hadn’t yet.
It might be helpful to point out that, because the add element / text block option didn’t turn up initially, I added it to the whole page then moved it in there at first. While that may have contributed, the fact that the adding option doesn’t show up is the bigger issue.
Anyhow, hope this is helpful to you. Thinking of tossing the page and starting over!
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