If you try to access the homepage of your Tuleap instance with some query parameters in the URL (e.g.
https://tuleap.example.com/?a=failure) you get a fatal error. That should not happen.
Trace:
Fatal error: Call to undefined method FlamingParrot_Theme::displayStandardHomepage() in /usr/share/tuleap/src/common/layout/SiteHomepageController.php on line 68
Call Stack
# Time Memory Function Location
1 0.0000 239104 {main}( ) ../index.php:0
2 0.0171 3994504 Tuleap\Request\FrontRouter->route( ) ../index.php:43
3 0.0392 7751912 Tuleap\Layout\SiteHomepageController->process( ) ../FrontRouter.php:110