This error occurs when an AppStoreConnect build is submitted for review but later rejected. Then the developer submits a newer build.

1.0.0(0) was submitted, 1.0.0(0) was rejected, 1.0.0(1) was submitted.

The answer can be found hidden in a post here by joelnewcomer

Steps

1. In the left column, click the current build ("Developer Rejected")
2. In the "Build" section, hover over the build and a red dot will appear on far right. Click it and delete the build.
3. Select the correct build and resubmit at top of page.

Error

Newer Build Available

Are you sure you want to submit this build for review? A newer build of your app is available. To submit the newer build, delete this earlier build and resubmit.