Error 581 - Type Library creation error

Type Library creation error - A system error occurred while creating the COM Type Library. The common cause of this error is using a data type not supported by Type Libraries. Type Libraries only support the following data types: BYTE, WORD, DWORD, INTEGER, LONG, QUAD, SINGLE, DOUBLE, CURRENCY, OBJECT, STRING, and VARIANT. Either suppress the creation of a Type Library by using the #COM TLIB OFF metastatement or by changing the Methods and Properties to only use supported data types.