COMException caused by Application.EditClear Method

I have a COMException caused by the following code

MSProject.Application mspApp;
bool result = mspApp.SelectColumn(Constants.ACTUALS_RECENT_INDEX, Missing.Value, Missing.Value, Missing.Value);
mspApp.EditClear(Missing.Value, Missing.Value, Missing.Value, Missing.Value);

The value of result is true.

Here's the exception:

System.Runtime.InteropServices.COMException (0x000003EC): An unexpected error occurred with the method.

at System.RuntimeType.ForwardCallToInvokeMember(String memberName, BindingFlags flags, Object target, Int32[] aWrapperTypes, MessageData& msgData)

at Microsoft.Office.Interop.MSProject._MSProject.EditClear(Object Contents, Object Formats, Object Notes, Object Hyperlinks)

Anybody knows the cause of this exception?

It sounds like the column that is getting selected is a read-only field such as ID, Unique ID, Project, etc.

Make sure the column being selected is the one you really want. You could do this by creating a table at run-time (and apply it) so you can be confident that the user has not changed the active view and/or underlying table.