app.json validation error: Invalid environment name:

Issue

When trying to perform a build you are getting the error app.json validation error: Invalid environment name even though there have been no changes to your app.json.

Resolution

Review Apps enforces a validation check on the keys under the "environments" section in the app.json file. If you include any key not listed in app.json schema section of the devcenter you will get a validation error.

• Allowed keys: test and review
• Keys you may previously have used but that will no longer work: staging, production