Exception from HRESULT: 0x800A03EC Error

Question

I am getting "HRESULT: 0x800A03EC" error when running Excel add-in with following code:

Excel.Range rng = ActiveSheet.Cells[x, y] as Excel.Range;                 string before = rng.Value2;  string cleanV = System.Text.RegularExpressions.Regex.Replace(before, @"\s+", ""); rng.set_Value(cleanV); 

When error happens X and Y are set to 1, thus Excel range is not violated. I searched extensively and tried a number of ways of setting the cell value (eg. Cells[x,y], range.set_Value()) but am at loss why this error happens and how to avoid it.

Any help is greatly appreciated.

Below are exception details:

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System.Runtime.InteropServices.COMException was unhandled by user code   HResult=-2146827284   Message=Exception from HRESULT: 0x800A03EC   Source=""   ErrorCode=-2146827284   StackTrace:        at System.RuntimeType.ForwardCallToInvokeMember(String memberName, BindingFlags flags, Object target, Int32[] aWrapperTypes, MessageData& msgData)        at Microsoft.Office.Interop.Excel.Range.set_Value(Object RangeValueDataType, Object value)        at ImportValidation.ThisAddIn.removeAnySpaces(Int32 x, Int32 y) in c:\Users\dshevelev\Documents\Visual Studio 2012\Projects\ImportValidation\ImportValidation\ThisAddIn.cs:line 354        at ImportValidation.ThisAddIn.ReadHeaders(Hashtable columnAddress) in c:\Users\dshevelev\Documents\Visual Studio 2012\Projects\ImportValidation\ImportValidation\ThisAddIn.cs:line 123        at ImportValidation.ThisAddIn.mapColumns() in c:\Users\dshevelev\Documents\Visual Studio 2012\Projects\ImportValidation\ImportValidation\ThisAddIn.cs:line 493        at ImportValidation.Ribbon1.button6_Click(Object sender, RibbonControlEventArgs e) in c:\Users\dshevelev\Documents\Visual Studio 2012\Projects\ImportValidation\ImportValidation\Ribbon1.cs:line 55        at Microsoft.Office.Tools.Ribbon.RibbonPropertyStorage.ControlActionRaise(IRibbonControl control)        at Microsoft.Office.Tools.Ribbon.RibbonPropertyStorage.ButtonClickCallback(RibbonComponentImpl component, Object[] args)        at Microsoft.Office.Tools.Ribbon.RibbonManagerImpl.Invoke(RibbonComponentCallback callback, Object[] args)        at Microsoft.Office.Tools.Ribbon.RibbonMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)        at Microsoft.Office.Tools.Ribbon.RibbonManagerImpl.System.Reflection.IReflect.InvokeMember(String name, BindingFlags invokeAttr, Binder binder, Object target, Object[] args, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParameters)   InnerException:  

Answer 1

Got same error in this line

 Object temp = range.Cells[i][0].Value; 

Solved with non-zero based index

 Object temp = range.Cells[i][1].Value; 

How is it possible that the guys who created this library thought it was a good idea to use non-zero based indexing?

Answer 2

This is a common but poorly documented Excel COM Error. I've seen it documented as "NAME_NOT_FOUND", meaning that Excel's COM layer is disabled, and can't find the COM property or method name.

I get this error consistently when running the COM code while Excel is 'busy', for example if you set a timer that will start the code, and the code starts running while the user is editing a cell or pressing down their mouse button, then you'll always get this error. This error only happens when the code runs on the main Excel thread, but seems to be the equivalent of error VBA_E_IGNORE = 0x800AC472, which you get when calling the Excel COM object model from another thread, while Excel is 'busy'.

The only workaround seems to be to retry (with some small delay) the COM call until it succeeds - when Excel is no longer 'busy'.