I have idea what happened recently with TestFlight. I have been uploading hundreds of bundles using TestFlight App and Xcode Archives.
With my recen target I get this and i have no idea where does it come from. I do everything the same as with my other apps:
As you can see even on screenshot, I have deployment target specified (minimum). I have also tried to specify minimum ios version in info file as instructed here (even if I believe I shouldn't do it in Info.plist):
https://developer.appcelerator.com/question/150078/invalid-ipa-must-specify-minimumosversiontestfligh
But it did not help.
It turned out my Info.plist was included in the "Copy Bundle Resoures" build phase list. I had to prevent it to be copied to the target. It can also be done by clicking on this file and remove if from "Target Membership" in the file properties panel. After removing in from target destination - everything went back to normal.