Deprecated (16384) : Since 5.0.0: SelectQuery::group() is deprecated. Use SelectQuery::groupBy() instead. /var/www/html/src/Controller/SchedulesController.php, line: 129 You can disable all deprecation warnings by setting `Error.errorLevel` to `E_ALL & ~E_USER_DEPRECATED`. Adding `src/Controller/SchedulesController.php` to `Error.ignoredDeprecationPaths` in your `config/app.php` config will mute deprecations from that file only. [in /var/www/html/vendor/cakephp/cakephp/src/Core/functions.php, line 377]
Warning (512) : Unable to emit headers. Headers sent in file=/var/www/html/vendor/cakephp/cakephp/src/Error/Renderer/HtmlErrorRenderer.php line=37 [in /var/www/html/vendor/cakephp/cakephp/src/Http/ResponseEmitter.php, line 65]
Warning (2) : Cannot modify header information - headers already sent by (output started at /var/www/html/vendor/cakephp/cakephp/src/Error/Renderer/HtmlErrorRenderer.php:37) [in /var/www/html/vendor/cakephp/cakephp/src/Http/ResponseEmitter.php, line 159]
Warning (2) : Cannot modify header information - headers already sent by (output started at /var/www/html/vendor/cakephp/cakephp/src/Error/Renderer/HtmlErrorRenderer.php:37) [in /var/www/html/vendor/cakephp/cakephp/src/Http/ResponseEmitter.php, line 192]
Error: Call to undefined method Cake\I18n\Date::getTimestamp()

Call to undefined method Cake\I18n\Date::getTimestamp() 📋

Error
Error in: ROOT/templates/Schedules/summary.php, line 48
ROOT/templates/Schedules/summary.php at line 48 (edit)
                        </td>
                        <?php foreach ($dates as $date) { ?>
                            <td class="text-center">
                                <?php
                                $hasSchedule count(array_filter($s->schedules, fn($sch) => $sch['date']->getTimestamp() == $date->getTimestamp()));
                                $hasTicketsUrl = !empty($s->tickets_url);
                                if ($hasSchedule) {
                                    if ($hasTicketsUrl) { ?>
                                        <a href="<?= $s->tickets_url ?>" target="_blank" rel="noopener noreferrer" title="Tickets kaufen"><class="icon icon-diefinals-star-circle"></i></a>

If you want to customize this error message, create templates/Error/error500.php