Had tried a backup program for 1st time, then upgraded to 2.8.5. Lost data, the backup program apparently failed too, but my host, Network Solutions, was able to restore it w/their backup.
All posts display fine on Web, and all but most recent (and longest and most important) post can be edited fine.
The one exception is the most recent post (again, it's longer than others, with more links too--which I mention in case that's a clue to resolution). I need to revise/make additions to this post frequently, and I don't like to work in HTML, prefer to use VISUAL tab.
The VISUAL tab (and HTML tab) work fine for OTHER posts, and the HTML works fine for this post, but the VISUAL doesn't work for this one.
What displays instead of VISUAL? A blank screen with occasional red streaks through it. If I click HTML tab, then click back to VISUAL tab, the HTML displays on that screen (replacing that blank screen with red streaks).
Also note that since this restore, the blank screen and red streaks show up under VISUAL tab for some of the other posts too--but only momentarily; they're promptly replaced with the appropriate VISUAL display. Unfortunately, that never happens with this single, and most important, post.
Help very much appreciated! I'm not super tech savvy, so please speak in layman's language. Thank you.