Thanks Glenn. One thing that jumps out is that WeBWorK may be having trouble storing sessions. It seems to be reauthenticating on every access of the admin page, and then (I imagine) losing the post data for the upgrade. Snippet:
[Thu Jul 10 11:08:22.990475 2025] WeBWorK::Authen::verify: BEGIN VERIFY
[Thu Jul 10 11:08:22.990654 2025] WeBWorK::Authen::do_verify: db ok
[Thu Jul 10 11:08:22.990978 2025] WeBWorK::Authen::CAS::get_credentials: service = https://path/to/webwork/webwork2/admin
[Thu Jul 10 11:08:22.991091 2025] WeBWorK::Authen::CAS::get_credentials: no ticket. Redirecting to https://path/to/cas/server/cas/login?service=https://path/to/webwork/webwork2/admin
[Thu Jul 10 11:08:22.991719 2025] WeBWorK::Authen::verify: END VERIFY
[Thu Jul 10 11:08:22.991825 2025] WeBWorK::Authen::verify: result 0
[Thu Jul 10 11:08:22.992007 2025] (eval): Bad news: authentication failed!
[Thu Jul 10 11:08:22.992085 2025] (eval): Rendering WeBWorK::ContentGenerator::Login
[Thu Jul 10 11:08:22.992614 2025] WeBWorK::Authen::store_session: The cookie session is expired.
We're using Authen::CAS. Also seeing this elsewhere:
[Thu Jul 10 11:17:04.535337 2025] WeBWorK::Authen::fetchCookie: fetchCookie: Session cookie does not contain valid information. Returning nothing.
I set these values in localOverrides.conf and then bounced webwork2, to no effect:
$CookieSameSite = "Lax";
$CookieSecure = 1;
$useSessionCookie = 1;
These were all commented out previously.