"There are one or more errors on the page." on iTunes Connect

Question

I am trying to upload a new iOS app version on iTunes Connect and am continuously getting the error

There are one or more errors on the page.

It is highlighting the language: "English (U.S.)":

Answer 1

In short, had to add all images to "App Preview and Screenshots".
I just had this issue, and this https://stackoverflow.com/a/38887524/795114 answer helped me to resolve it.
Not sure why, but when removed other images and left only biggest for iPhone and iPad, this issue appeared. Seems almost like iTunes Connect bug.

Update
Now it worked for me. Successfully published new release by resubmitting all new images.
For more clarity, few steps:

1. Firstly deleting all images
2. Then enable "Use 5.5-Inch Display" (as also mentioned by Mashhadi)
3. Upload 5.5-Inch iPhone (and/or 12.9-Inch for iPad) images and press save