It seems that the problem was caused by me having versions our of synch. My app was on version 1.0 but and my build on Version 1.0 however (due to some confusion on my part) expired builds for version 2.0 and 3.0 still existed. I resolved by defining the app as version 4.0 in appstore and rebuilt a version 4.0 in xcode. Important to have versions in synch. My gripe with the extremely poor user interface on Appstore Connect continues - you would have thought I'd get an error or warning message for this - it seems easy enough - but nothing. Very frustrating.

I had expected Apple to provide a monitoring capability so that I could see why my app was failing. However, I have had to build this myself. I have logged all activity to the user's device which the user can then access and send me with a particular keystroke combination. I deployed this and within minutes found the bug in the app.

On the App Distribution tab, when I submit for approval, I get an error requiring me to choose a build. When I select Add Build, I get the window with all my uploaded builds but I cannot select them, the radio buttons are disabled. Good point, I have added translations (nothing suggested they were mandatory) and that has reduced the error list of things preventing me from submitting for approval. I think I may need my subscription to be approved before I add in a trial period, so need to solve point 1 above first. On app versions, is there an enforced sequence? I am trying to test Version 3.0 of my app in Test Flight, I uploaded a bundle from Xcode with Version 3.0 but thought that might be the issue so expired it and created a 1.0 bundle. So the build options to select are 1.0 that I want to test, but 3.0 is also in the list.