There's a quiet kind of desperation that comes when a tool you've used successfully suddenly turns on you. That's exactly where this user finds themselves: error bars that once appeared now vanish the moment they press accept. They've tried horizontal tables, vertical tables, copying data, pasting data, and starting from the original source. Nothing works. And so they're left breaking down over what should be a simple chart adjustment. We get it. But here's the thing about spreadsheets: they don't fail for no reason, and the fix is rarely as random as it feels.
What's happening here is almost certainly a mismatch between how Excel expects the error bar data to be structured and how it's being entered. The user mentions selecting the deviation and then watching it disappear. That's a classic symptom of a reference that Excel interprets as a single value or an invalid range. When you paste or type a range into the error bar dialog box, Excel doesn't always handle it the way you'd expect. It might be reading the selection as a scalar, or it might be silently converting the range into something it thinks is more appropriate. The result is the same: the dialog box closes, the bars don't render, and the user is left with a chart that looks exactly as it did before. This isn't a mystery. It's a known quirk, and it has a known workaround.
The practical takeaway here is to stop fighting the dialog box and start working with the underlying structure. Instead of selecting the deviation values directly from the chart or the formula bar, go into the error bar customization pane and manually type the range using the full worksheet reference, like `=Sheet1!$C$2:$C$10`. That forces Excel to treat the data as a continuous array rather than a loose selection. Also, check whether the data includes headers or blank cells. Excel is finicky about that. A stray blank row can cause the entire range to be ignored without any warning. And if the user is using a horizontal table, they need to make sure the error bar direction matches the table orientation. It sounds simple, but it's the kind of detail that gets lost in the heat of frustration.
This is not a story about a broken feature. It's a story about how easily small structural mismatches can derail even the most straightforward tasks. The user isn't incompetent. They're not careless. They're just up against a tool that demands precision in ways that aren't always obvious. The solution is to slow down, strip the process back to its simplest form, and rebuild the error bar reference from scratch. Start with a clean chart, add the error bars using the default option, then overwrite the range with a fully qualified reference. If the bars still vanish, try placing the deviation data in a single column adjacent to the original data and re-enter the range. One of these will work. We've seen it happen enough times to be confident. The chart isn't broken. The approach just needs to be more deliberate.