Error Messages (E) A B C D E F G H I J K L M N O P Q R S T U V W X Y Z #Error E_UNEXPECTED (0x8000FFFF) received when filling Dataset object in .NET project ActionUsing ODBC Driver to connect to Progress database from a C# program. ResultThe following error occurs when trying to fill the DataSet object. Error: E_UNEXPECTED (0x8000FFFF) CauseWhen ODBC drivers are used within a Visual Studio .NET program, Microsoft has benchmarked this only via a separately installed ODBC Managed Data provider component.The OLE-DB Providers should be used from a Visual Studio .NET program only via OLEDB Managed Data provider. Resolution:Using ODBC Managed Data provider resolves the problem. You have to download this separately from Microsoft and install it as an add-on component -- ODBC .NET Data Provider -- to the .NET Frameworks. It can be downloaded here:http://www.microsoft.com/downloads/details.aspx?FamilyId=6CCD8427-1017-4F33-A062-D165078E32B1&displaylang=en It installs to Start/Programs/ODBC .NET Data Provider and includes relevant documentation.In Visual Studio, you have to manually add the new component's reference to your Project (under Project menu, "Add Reference...") as "Microsoft.Data.Odbc.dll".|Evidence Creating a Windows ODBC Trace