I re-posted a partial fragment because that fragment was the only portion that I had altered. Ergo, the error HAD to exist in that portion of the code. (not always true, but certainly applicable with the tiny layout file I'm using) And, sure enough, it did.
Thank you SO MUCH!
It never even occurred to me that the problem might be the compiler expecting only one kind of quotation mark. Q.Q
Should be able to get it working now, but I'll post again if something unforeseen crops up. (=