Using .NET CLR 4.0 or greater
When using the Infragistics® Excel® object library and exporters to generate a Microsoft® Office® 2007 compliant xlsx Excel File, the .NET Framework CLR version 4.0 or greater is required. In this scenario, you will reference the Infragistics.Excel Assembly. The compression and packaging functionality that is built into the xlsx file creation logic relies on the .NET Framework CLR3.0