Tips and Tricks: Troubleshooting

"Clear all caches" when something goes wrong

During the development of your site it might happen, that you can't see changes in your browser or that the site acts strangely. Frequently the problem can be very easily solved by clearing the cache. To do so go to Configuration > Development > Performance and press "Clear all caches".

Drupal Clear Cache

"From address" doesn't work in Forward Module. How to solve the issue?

If the "From address" is left blank the site email address is used instead of the address entered by the user. This howto shows you how to solve the issue quickly.

Troubleshoot error message after update/installation of module/theme with "undo"

Occasionally it might happen that you get an error message or even a fatal error after updating/installing a module or theme. If so, try to undo the recent changes first.

Issues page for Drupal Views

"The website encountered an unexpected error. Please try again later." (Drupal 8)

You might get "The website encountered an unexpected error. Please try again later." after the installation or uninstallation of a module, when you login with the admin user or in general. Possible solutions:
  • run update.php
  • move the module installed/uninstalled outside the Drupal installation
  • Clear cache within the database by emptying all cache tables

Google Maps v3 api stop working

The Google Maps API allow for the embedding of Google Maps onto web pages of outside developers, using a simple JavaScript interface or a Flash interface. It is designed to work on both mobile devices as well as traditional desktop browser applications. The API includes language localization for over 50 languages, region localization and geocoding, and has mechanisms for enterprise developers who want to utilize the Google Maps API within an intranet.

If the Google Maps v3 API stops working, try the following:

Composer require error: can't delete

1. This command will fix it temporarily:

chmod u+w web/sites/default

2. But Drupal will harden permission again soon. To turn it off add this to settings.php:

$settings['skip_permissions_hardening'] = TRUE;

Note: 1. seems to work, 2. not


Drupal migration: Export from Drupal 8, import into Drupal 9

The migration path from Drupal 8 to Drupal 9 is not always smooth and easy. But there are also other good reasons to start with a fresh Drupal 9 website and to migrate the content from Drupal 8, as a migration is always a chance to improve important dimensions of a website such as the design or SEO (Search Engine Optimization). If you chose this path you can export/import the data as follows with CSV-Files and the help of some spreadsheet processing.


Drupal themes to be compared