Изменил обработчик на:
catch(Exception e)
{
result2 = e.Message;
}

Вот что в result2:
Retrieving the COM class factory for component with CLSID {0AF427E7-03B9-4673-8F21-F33A683BCE28} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).