4
When you say they can't be seen, do you mean at all, or that you see the header but there is only space where the content should be? If it's the 2nd one, try highlighting the area that appears blank. The text is probably there.
I just helped someone on another forum with the same issue. When I checked the page source, the text in her custom block was there.
For a quick fix, I enclosed everything in her custom block with
tags and the text magically appeared.
That's not the proper fix, but it made her block visible until the problem could be found and fixed properly.
Hope that helps.
John