Web-panel admin login issue after upgrading from SBPP 1.6.4 to 1.7.0

[Mecha-Weasel]

What are the steps to reproduce this issue?

1. Have SBPP 1.6.4 setup to use Steam authentication for Admins in the web-panel
2. Upgraded in-place from SBPP 1.6.4 to 1.7.0 successfully (with required upgrade to PHP 8.1+ in Apache modules), ran /updater script, etc.
3. Try to login to web-panel with Steam authentication.

What happens?

Errors displayed after logging-into Steam, during re-direct back to SBPP web-panel:

Dashboard works fine (non-Admin), but trying to login as an Admin is broken.

What were you expecting to happen?

Successfully authentication in Steam and returned-to SBPP web-panel, as it did successfully under prior SBPP 1.6.4 installation.

Any logs, error output, etc.?

See attached screenshot.

Any other comments?

Self-explanitory.

What versions of software are you using?

Operating System: Debian 11, 64-bit
SourceBans++ Version: Was 1.6.4, now 1.7.0
PHP Version: 8.2
MySQL Version: MariaDB 10.5.19
Link to your project: n/a
Link to a phpinfo() output: n/a

[Mecha-Weasel]

PS: Rolled-back web-panel to 1.6.4 (I saved a backup copy of the entire folder), and set Apache PHP back to 7.x; and everything works as before.

[Rushaway]

Make sure to have the folder "templates_c" and using PHP 8.1.