A couple of points.

First, the only kind of a chart that supports error bars is one with a
numeric X axis (XY Scatter chart, for example).

Second, I'm not sure how you got that code. My usual way of generating a
starting point is to use the macro recorder. With it, the code I got was
ActiveChart.SeriesCollection.NewSeries
ActiveChart.SeriesCollection(1).XValues = "=data!R1C1:R25C1"
ActiveChart.SeriesCollection(1).Values = "=data!R1C2:R25C2"
ActiveChart.SeriesCollection(1).Select
ActiveChart.SeriesCollection(1).ErrorBar Direction:=xlX, Include:= _
xlPlusValues, Type:=xlCustom, Amount:="=data!R1C3:R25C3"
ActiveChart.SeriesCollection(1).ErrorBar Direction:=xlY, Include:= _
xlPlusValues, Type:=xlCustom, Amount:="=data!R1C4:R25C4"

which is easily modified to
With ActiveChart.SeriesCollection.NewSeries
.XValues = "=data!R1C1:R25C1"
.Values = "=data!R1C2:R25C2"
.ErrorBar Direction:=xlX, Include:= _
xlPlusValues, Type:=xlCustom, Amount:="=data!R1C3:R25C3"
.ErrorBar Direction:=xlY, Include:= _
xlPlusValues, Type:=xlCustom, Amount:="=data!R1C4:R25C4"
End With

The above works just fine with a XY Scatter chart but fails with a couple of
the other types that I tested.

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article .com,
says...
Hi everyone,

I am having trouble with some vba code to add error bars to a new
series I am creating. When I run the following code I get a 'ErrorBar
method of Series class failed' error on the first .errorbar line. Can
anyone help me out?

With ActiveChart.SeriesCollection.NewSeries
.name = GraphForm.tbxSeriesName.Value
.Values = Worksheets("Data").Range("B1:B25")
.XValues = Worksheets("Data").Range("A1:A25")
.ErrorBar Direction:=xlX, Include:=xlErrorBarIncludeBoth,
Type:=xlCustom, _
Amount:=Worksheets("Data").Range("C1:C25")
.ErrorBar Direction:=xlY, Include:=xlErrorBarIncludeBoth,
Type:=xlCustom, _
Amount:=Worksheets("Data").Range("D1:D25")
End With

There is probably a better way to do this (add error bars to a new
series) but I am not familiar enough with Excel programming to know
what it is. Thanks for any help in advance.