App Store submission failed after site redesign.

same problem here (on iOS app, it did not gave problems on Maccatalyst apps)
I just contacted appstoreconnect.com, they wasn't aware of this problem and do not provide a solution for it
try to contact them too

I found also a post on stack overflow, with a possible solution, but it didn't worked for me:
https://stackoverflow.com/questions/62442805/ios-app-submit-review-to-app-store-failed/62462336#62462336

ive gotten this too, it said an error has occurred and after i hit refresh, it was In Review. So i think its fine, just a bug on the web side. I called support and they said everything looked fine. I Do have a contact with them there i will link this forum post and the stackoverflow post so they can dig deeper into it.

Today I tried again the Appstore connect error message was improved:

• the error show was still there, but additional informations were available

• my "new in this release" notes wasn't there anymore and it was necessary to add them manually again for each language

• finally I arrived to release my apps

what did caused my release notes disappear? I discovered this is an error with the Fastlane tool I'm using for deploys of binaries and metadata, it seems that with metadata it is not working anymore (since the App Store connect redesign) and my notes for the latest version wasn't there

with the correct error message I solved the problem

I hit this issue 2 days ago and was lucky today.

It is recommended to check the browser console on the submit button click to see the server response to see if you can get a more descriptive error. I got a generic error hence it didn't help.

Things to try out, as recommended by Apple support.

1. Try Safari this time if you were trying from other browsers.
2. In Safari, App Store Connect > Make sure to remove the old build > click save > refresh page > Select the latest build > click add to review.
3. If that didn't work retry step 2 from a different manager account this time.
4. If you are still facing an issue take a full-screen video record of this and give it to them at https://feedbackassistant.apple.com/ They will respond in their business days.

As I tried today (29 Jan 2022) the app store connect website looked different than how it looked one week ago. and today I was able to submit it successfully from the Safari browser. I'm guessing Apple did some upgrades and servers were not fully ready when I tried (multiple times) past 24 hours