Umbraco v13.7.0 with basic authentication in IIS enabled causes backoffice login 500 error

[tonyw195]

Which Umbraco version are you using? (Please write the exact version, example: 10.1.0)

13.7.0

Bug summary

• Just upgraded from v13.6.0 to v13.7.0.
• Logged into backoffice.
• Backoffice try's to login user but causes a 500 error.
• Problem does not happen when we turn off basic authentication in IIS.
• We have always run basic authentication in IIS on all versions of Umbraco 13 and never experienced this issue.

Specifics

No response

Steps to reproduce

• Have Umbraco 13.7.0 running.
• Basic authentication is enabled in IIS for a 401 challenge.
• Log into backoffice.
• Backoffice try's to login user but fails with a 500 error.

Expected result / actual result

Backoffice log's in user but instead causes 500 error.

[github-actions]

Hi there @tonyw195!

Firstly, a big thank you for raising this issue. Every piece of feedback we receive helps us to make Umbraco better.

We really appreciate your patience while we wait for our team to have a look at this but we wanted to let you know that we see this and share with you the plan for what comes next.

• We'll assess whether this issue relates to something that has already been fixed in a later version of the release that it has been raised for.
• If it's a bug, is it related to a release that we are actively supporting or is it related to a release that's in the end-of-life or security-only phase?
• We'll replicate the issue to ensure that the problem is as described.
• We'll decide whether the behavior is an issue or if the behavior is intended.

We wish we could work with everyone directly and assess your issue immediately but we're in the fortunate position of having lots of contributions to work with and only a few humans who are able to do it. We are making progress though and in the meantime, we will keep you in the loop and let you know when we have any questions.

Thanks, from your friendly Umbraco GitHub bot 🤖 🙂