Properties of the metadata accessors use types that match native metadata types as close as possible. Some of these types, however, do not belong to the .NET Common Language Specification, i.e., they are not guaranteed to be supported in all .NET development environments. These types include: System.Sbyte, System.UInt16, System.UInt32 and System.UInt64. In particular, Visual Basic .NET 2003 does not support these types (Visual Basic .NET 2005 does).

If you use a development environment does not support these types, convert them to the next more capacious supported type. You can use System.Convert class for this.

Use the opposite conversion for adding values to metadata.