Whatever else the v11.5 update might do, it breaks the automatic "Always create backup" function. Well, actually...it doesn't actually break it completely, but it introduces an obnoxious bug. Here's what happens.

If there's no backup file in the first place, Excel will make one automatically when you save the original file. Then let's say you keep working in Excel, saving incrementally as you go. That's when the bug shows up. EVERY time you try to save the document, Excel displays a prompt saying "Cannot create backup file." Nothing happens until you dismiss the prompt, which offers you the option to "Cancel" the save operation, or click "OK", which presumably saves the file without saving a backup. But that's not what happens. When you click "OK", Excel saves the file, and DOES save a backup of the last saved version, exactly as it should, and exactly as it has always done. The difference is that it gives that damned useless prompt now in v11.5, telling you it can't create a backup, and then goes ahead and creates the backup anyway.

How perfectly MSian — take an application that had a normal, useful feature that worked properly, and introduce a bug that makes it a nuisance to use that feature.

It's bad enough that MS had to gut Office 2008 (removing VBA), making it necessary to continue to use Office 2004 until they restore VBA functionality in the next version of Office (assuming they do that). But to add insult to injury, they have to break features in Office 2004 that previously worked OK. Sheesh...