Hi,
Thank you for posting your query to us.
I am afraid that I was not able to reproduce the issue. I have used the following code to rotate the chart label.
Me.ChartWebControl1.PrimaryXAxis.ValueType = ChartValueType.DateTime
Me.ChartWebControl1.PrimaryXAxis.DateTimeRange = New ChartDateTimeRange(CDate("01/Nov/2007"), CDate("30/Nov/2007"), 5, ChartDateTimeIntervalType.Days)
Me.ChartWebControl1.PrimaryXAxis.DateTimeFormat = "dd/MM/yyyy"
Me.ChartWebControl1.ChartArea.PrimaryXAxis.LabelRotate = True
Me.ChartWebControl1.ChartArea.PrimaryXAxis.LabelRotateAngle = 90
Me.ChartWebControl1.ChartArea.PrimaryXAxis.LabelAligment = StringAlignment.Center
I have created a simple sample to test this issue with different version and it works fine.
Please look into the sample images which has taken from different versions.
http://www.syncfusion.com/support/user/uploads/SampleImage_F70406_416d86cd.zipThe sample is available in the following link.
http://websamples.syncfusion.com/samples/Chart.Web/6.1.0.34/70406/main.htmPlease have a look at the above sample and if still the issue exists let me know at which version you are getting the issue so that we could sort out the cause of the issue and provide you a solution.
Regards,
Suba