Labview FPGA compile using NI App Builder API: Build.vi

Hey,

I'm having trouble starting compilations for FPGA targets (I have the modules installed) using the NI_App_Builder_API: Build.vi method which looks like it only needs a spec to build. Has anyone else had success with this? 

I also have tried niFpgaBuild_GenerateCode which also has an error (I can build the FPGA fine manually). Any ideas?

Thanks,

Rik