I get the same error. I got the app removed from sale due to screenshots not in compliance with the guidelines. After that I have not been able to add a new verion to review and get this generic error message. Have you been able to resolve the issue yet?
I suspect it has to do with the availability of the app.
skarh
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Man oh man, I've been stuck on this for 24h now. And of course just after I posted this, I changed to another USB-C port in the MacBook and sure enough, the device appeared. Lol.