ArgumentOutOfRangeException was unhandled by user code Yet works on another form

[jmcilhinney]

The most likely item in that line is the series, so the first thing to do is to put a breakpoint on that line. When execution stops on the breakpoint, highlight this part:

TechAnalTopLeftGraph.Series(1)

and press Shift+F9. If it shows you the same error, then the Series is the issue. If it doesn't show you any error message, then the series is not the issue, at which point you can look elsewhere in the line for the cause of the problem, but it doesn't seem like any other part of that should throw THAT particular exception.

I wonder whether you might be thinking of an IndexOutOfRangeException rather than an ArgumentOutOfRangeException. The latter can be generated by any method argument of any type, if only certain values of that type are acceptable. The former is restricted only to integral collection or array indexes.