I recently uploaded an app to the app store and its been processing for a few days now. I went in this morning to check everything out, and on the top bar of iTunes connect,
Check your email, it tells you exactly what is wrong. In itunes connect it simply says "This build is invalid" which is kind of useless. If you check your email it will most likely be a testflight issue as you included the sdk in your build and its integrated into itunes connect now:
"TestFlight SDK - TestFlight no longer requires an SDK to enable beta testing, crash reporting and analytics. To continue using TestFlight, set up Beta Testing in iTunes Connect and remove references to the SDK from the following executables:"