Why do I see H99 errors or "400 Bad Request" on Private Spaces?

Resolution

Migrate the app to the upgraded routing infrastructure for Private Spaces. Please review the Dev Center article Routing in Private Spaces for the detailed procedure.

Heroku upgraded the routing infrastructure for Private Spaces on October 26, 2016. The upgraded routing infrastructure supports higher request throughput and reduced latency. Private Space applications created before this date is on the original routing infrastructure if the following command shows Via: 1.1 vegur while an app on the upgraded routing infrastructure shows Via: 1.1 dogwood-router or Via: 1.1 spaces-router followed with an internal version number.

curl -s -I http://<app-name>.herokuapp.com/ | grep Via:

The upgraded routing infrastructure provides improvements in the areas including more accurate error code reporting and larger cookie and header support. The original routing infrastructure in Private Spaces was reporting H99 errors in place for more specific H errors. Please refer to the Dev Center article Private Space Routing Infrastructure for the details about the upgraded routing infrastructure.