Unable to login to new Canvas instance (stable/2026-05-06)

[Anand Srinivasan]

Hi guys,

I just setup a new canvas instance to see this error upon logging in.

Production log says that the login is a success at first, followed by a redirect to https://<url>/login?needs_cookies=1; The final status is 401 unauthorized. The credentials are correct.

Please help identify what might be wrong.. 

Thanks,

Anand

[Andrey Gangan]

I think this branch was not ready for prod.

try to clean redis cache 

or try another browser

суббота, 20 июня 2026 г. в 09:00:30 UTC+3, Anand Srinivasan:

[Anand Srinivasan]

Have tried both and a lot more.. nothing has worked so far. Is there a reliable way to check which branch is ready for prod?

Thanks,

Anand

[Andrey Gangan]

just use prod.

if still nothing, double check everything.

but remember about the missing dependency in the prod branch https://github.com/instructure/canvas-lms/issues/2626

четверг, 25 июня 2026 г. в 09:07:26 UTC+3, Anand Srinivasan:

[Andrey Gangan]

by the way, I would check production.log in projects log folder

четверг, 25 июня 2026 г. в 09:12:41 UTC+3, Andrey Gangan:

[Anand Srinivasan]

[RESOLVED]

Needed an upgrade to the passenger version.

The POST's Set-Cookie came back as ["cookie1", "cookie2", "cookie3"] — a Ruby array printed as literal text into a single header instead of three separate Set-Cookie: lines. That's the Rack 3 convention (multiple cookies handed to the app server as an array) being mishandled by an app server that predates Rack 3 support. Browsers salvaged the first fragment and silently discarded the rest — including the session cookie, leading to this error, which appeared in older branches too.

Thanks to everyone who reached out and helped.