When trying to invoke a RealData product, you may get this message:
There was a problem sending the command to the program.
This may happen if the ‘Ignore other applications that use Dynamic Data Exchange (DDE)‘ option in Excel is set. Please see the Microsoft Knowledgebase article below for instructions on turning this option off, even though the error message shown there is different:
https://support.microsoft.com/en-us/kb/3001579