Your front panel is nicely laid out. But can I make a spelling suggestion? The word is "Standby" not "stanby". Things like misspelled words can make a program look unprofessional when otherwise the user interface looks very clean and professional.
Unfortunately for your error message, it seems like you have the VISA install correct now, but something else is happening. Do you know what is going on inside the Emant VI's? I'm thinking they are trying to do something unusual with the serial port that the NI-VISA drivers don't permit. I would suggest running NI-Spy before you start the program and then run the program. It will log the interaction between LabVIEW and the serial port. It may give more information as to what is going wrong.