Server error when switching to other account

[elsdvlee]

Environment

Windows
I was using this communica webclient: https://comunica.github.io/comunica-feature-link-traversal-web-clients/builds/solid-single-pod/

Description

I can sucessfully log in with one account, and perform a query. Then I logout and try to log in with another account but get following error screen:

After clearing the cookies, I can log in again.

[Joachim Van Herwegen]

Notes for looking into this:

This is an error thrown by the oidc-provider library, probably because there is still a cookie of the previous session which somehow conflicts with the new session. Might also be related with how we forgot WebIDs when changing those here? Or perhaps we need to clear session cookies at some point when a new user logs in.