I originally created a document at a particular page size, but am having to make the page size smaller, and therefore adjust all of the text frames. Throughout most of the document, things have gone according to plan. But about midway through, the text disappears when I resize a text box. Hyphenation is turned off (I need it turned off for the finished product - also, this error doesn't happen when I turn hyphenation back on), and no break is turned off. There are no underlying or overlapping boxes with text wrap, just a single text frame on a single page. Any ideas? I've already downloaded the prerelease and run into the same issue there.
Can you post a screenshot of the page with the hidden characters visible? Maybe there is a column break?
Your problem is that long string of text separated by non-breaking spaces. If you don't allow hyphenation there is no way for InDesign to fit the entire string on a line.