The PHP error log file contains the following error:
[11-Nov-2019 18:32:12 Europe/Berlin] PHP Fatal error: Uncaught Error: Call to a member function getName() on null in /usr/share/nginx/www/spenden.wikimedia.de/release-201911111 72411/vendor/wmde/fundraising-donations/src/UseCases/AddComment/AddCommentUseCase.php:91 Stack trace: #0 /usr/share/nginx/www/spenden.wikimedia.de/release-20191111172411/vendor/wmde/fundraising-donations/src/UseCases/AddComment/AddCommentUseCase.php(66): WMDE\Fundraising\DonationContext\UseCases\AddComment\AddCommentUseCase->newComment(Object(WMDE\Fundraising\DonationContext\Domain\Model\Donation), Object(WMDE\Fundraising\DonationContext\UseCases\AddComment\AddCommentRequest)) #1 /usr/share/nginx/www/spenden.wikimedia.de/release-20191111172411/app/Routes.php(225): WMDE\Fundraising\DonationContext\UseCases\AddComment\AddCommentUseCase->addComment(Object(WMDE\Fundraising\DonationContext\UseCases\AddComment\AddCommentRequest)) #2 /usr/share/nginx/www/spenden.wikimedia.de/release-20191111172411/vendor/symfony/http-kernel/HttpKernel.php(151): WMDE\Fundraising\Frontend\App\Routes::WMDE\Fundraisi in /usr/share/nginx/www/spenden.wikimedia.de/release-20191111172411/vendor/wmde/fundraising-donations/src/UseCases/AddComment/AddCommentUseCase.php on line 91 [11-Nov-2019 18:32:13 Europe/Berlin] PHP Fatal error: Uncaught Error: Call to a member function getName() on null in /usr/share/nginx/www/spenden.wikimedia.de/release-20191111172411/vendor/wmde/fundraising-donations/src/UseCases/AddComment/AddCommentUseCase.php:91
Please investigate this error and the resulting user flow, I guess it occurs when a donor donates anonmously (any payement type except "Lastschrift") and then tries to comment non-anonmously (choosing non-anonmously in the form).