Testflight does not allow iOS 7.1 app compiled with iOS 8.1 SDK to install on iOS 7.1.2 iPhone

Question

When I'm in the Testflight web app I see some apps I've built earlier that support iOS 6 and up, but the app I'm working on now does not show up. It's an iPhone 4 running iOS 7.1.2 and testers report the same issue. My device shows also like this version under "devices" and I already tried to reconnect the device, to no avail.

The minimum OS as displayed in Testflight when I go to incompatible builds is listed as iOS 7.1. At this point I'm a bit baffled about what to do. At this point I'm a bit baffled. Already tried to check all build settings and re-uploading the build to Testflight.

Answer 1

Twice I had the same error. Third time I've uploaded the same code with a different build number but with the same settings it worked. I suspect a glitch in the Matrix, a temporary problem on the side of Testflight