After building an Android app with the ADT plugin for Eclipse, an error occurs when attempting to upload the app to App Center.
Could Not Upload : Unable to process app. Please double-check that you provide a valid app.
Google Developer forums had a post with this issue. While the issue was not present upon uploading to App Center, it was observed by developers trying to upload apps to the Play Store.
Here is that forum post:
https://code.google.com/p/android/issues/detail?id=46311 (Form: Android Open Source Project - Issue Tracker)
The issue was fixed in the ADT plugin versions R22 and up. Please download the a version of ADT that meets this criteria as laid out in the following article:
App Center 4.4.x
Android Developers Tools (ADT) - plugin version 21.0.1 and lower.
Android OS. v4.x