The app is uploaded without errors, but when I press the install button I get this message:
I'm using macOS Sierra 10.12 and Xcode 8.
This has never happened to me in old versions of Xcode. What could be wrong?
TestFlight is currently unavailable, i can't either install from TestFlight or see any of my builds in Itunes Connect. Also my app was in processing for 4 hours, then this happened.
Please check here https://developer.apple.com/system-status/
Update: Confirmed by Apple 
I had the same issue. I never had an issue with setting or not setting the encryption flag. So I thought maybe they made a change today. So I added the key in and it still didn't work. I decided to remove the last build from testing then re-added it. That worked for me. I was immediately able to download and install the app. Hope that helps.
Build another version and upload to Itunes Connect. Maybe your time uploading have some problem from Apple Server. I have just checked.
Seems to be working for me this morning now. Incidentally Brad my app had GPUImage embedded in it so just for giggles I also added the "App Uses Non-Exempt Encryption." switch to the embedded GPUImage plist. Not sure if that was relevant.
来源：https://stackoverflow.com/questions/40226636/the-encryption-information-is-unavailable-try-again-testflight