TypeError: Argument 2 passed to Symfony\Component\Routing\RouteCollection::add() must be an instance of Route, boolean given, called in RouteProvider.php on line 382 

Drupal Update / Upgrade Error:

Mit "composer update --dry-run" Aktualisierungen erfassen und als E-Mail benachrichtigung an "admin/webmaster" schicken:

Composer Output an PHP-Variable:

<?php 

$output = shell_exec( "composer update --dry-run 2>&1" ); 

echo $output;

Error: Solr requires java, please install or set JAVA_HOME properly

Was ist die Lösung?

Solarium Error:

Solarium 5.0.2 is too old and has known issues. In order to get composer to upgrade solarium to a recent version a core patch or a workaround is required. Have a look at this Core issue and this Search API Solr issue.

Error: Apache Solr (Solr-Server Version: 8.5.2) & Drupal 8.9 (search_api_solr: 3.9)

Your config-set contains manually added customizations. Be aware that these will be lost when the config-set needs to be regenerated.

Fehlermeldung: 

SQL Query:

Fehler:

Error: Maximum function nesting level of '256' reached, aborting! in html_entity_decode() (line 386 of /home/512/web/core/lib/Drupal/Component/Utility/Html.php)

Lösung (php.ini):

xdebug.max_nesting_level = 1024

Wenn man DB-Backup wiederherstellen möchte:

drush sql:cli < my-db-backup.sql