Compile and Download does not download code and no error message appears. What is going on? | FAQ (Frequently Asked Questions) | Forum

In Arduino IDE version 1.6.12 there is an issue with the command line interface to the compiler in which the Arduino Compatible Compiler for LabVIEW uses to download your code to the board.  There is already an open issue with the Arduino IDE developers and hopefully this will get resolved in the next Arduino IDE release.  For now, try downgrading your Arduino IDE to 1.6.11 or previous or they have provided a workaround posted here.