Sorry for the delay to answer this. I downloaded the 4.14 SDK this morning and I had the same problem Dany is having. All the FlatSpark sources are there, but the .swc is not getting generated in the libs folder.
I downloaded the SDK via the installer. I'll try to download it again, as Erik instructed. I don't know if this relates to the problem, but I'm trying this on Windows. Erik and Dany, which OS are you using?