Parece ser um comportamento esperado devido a encerramento da API v1 :
As previously announced, API v1 is being retired on Thursday, September 28th, 2017.
On this date, API v1 endpoints will return a
400
error with this message:{“error”: “v1_retired”}
. This means any integrations or applications still relying on API v1 endpoints may stop working.
Então eu relatei o bug 1762408 para o LaunchPad.