Resetting Passwords

Backend Administrator Password

When the password for a backend user needs to be reset, log into the backend as a different user and use the System > Backend Users tool to reset the password. Note that only backend users with administrative rights can access the Backend Users tool to make this change.

If an alternative administrator account is not available or it doesn't have the appropriate access, open the Install Tool directly using the following address to create a new administrative user:


The Install Tool requires the "Installation Password" that would have been set when TYPO3 was installed.

The install tool login

Enter the install tool password

Once logged in to the Admin Tool go to Maintenance > Create Administrative User and select Create Administrator. Here you can create a new administrative user.

Button to create an administrator

Create a new administrative user

Form to create an administrator

Fill in the fields for the new administrative user

Use this new administrator account to log into the TYPO3 backend. In the module Backend Users you can change the passwords of existing users, including administrators.

Install Tool Password

Write access to typo3conf/LocalConfiguration.php is required to reset the Install Tool password.

Before editing this file, visit:



Enter the new password in the dialog box. As the new password is not correct, the following response will be returned:

"Given password does not match the install tool login password. Calculated hash:

Copy this hash including the $argon2i part and any trailing dots.

Then edit typo3conf/LocalConfiguration.php and replace the following array entry with the new hashed password:

'BE' => [
   'installToolPassword' => '$argon2i$v=xyz',

Debug Settings

During troubleshooting, in the "Settings > Configuration Presets" section of the Install Tool, under "Debug settings", the "Debug" preset can be changed to show errors in the frontend.

Configuration Presets Card

Choose a configuration preset

Debug Presets

Choose the debug preset

The following TypoScript setting can also be added to the root template for the site to show additional debugging information. This is particularly useful when debugging Fluid errors:

config.contentObjectExceptionHandler = 0

Additionally, the following logs should be checked for additional information:

  • Webserver log files for general problems (e.g. /var/log/apache2 or /var/log/httpd on Linux based systems)
  • TYPO3 Administration log in SYSTEM > Log via TYPO3's backend.
  • TYPO3 logs written by the Logging Framework located in var/log or typo3temp/var/log depending on the installation setup.


Cached Files in typo3temp/

TYPO3 generates temporary "cached" files and PHP scripts in <var-path>/cache/ (either typo3temp/var/cache or var/cache depending on the installation). You can remove the entire <var-path>/cache directory at any time; the directory structure and all the caches will be re-written the next time a visitor accesses the site.

A shortcut to remove these caches can be found in the Install Tool, under Important Actions. This might be useful in the event of your cache files becoming damaged and your system not running correctly. The Install Tool won't load any of these caches or any extensions, so it should be safe to use regardless of the corrupt state of the caches.

Amongst other caches, under <var-path>/cache/code/core/ you will find:

-rw-rw----   1 www-data   www-data   61555  2014-03-26 16:28   ext_localconf_8b0519db6112697cceedb50296df89b0ce04ff70.php
-rw-rw----   1 www-data   www-data   81995  2014-03-26 16:28   ext_tables_c3638687920118a92ab652cbf23a9ca69d4a6469.php

These files contain all ext_tables.php and ext_localconf.php files of the installed extensions concatenated in their loading order. Therefore including one of these files would be the same as including potentially hundreds of PHP files and should improve performance.

Possible Problems With the Cached Files

Changing the absolute path to TYPO3

If you change the path of the TYPO3 installation, you might receive errors like "Failed opening ..." or "Unable to access ...". The problem is that absolute file paths are hard-coded inside the cached files.

Fix: Clean the cache using the Install Tool: Go to "Important Actions" and use the "Clear all caches" function. Then hit the page again.

Changing Image Processing Settings

When you change the settings for Image Processing (in normal mode), you must take into account that old images may still be in the typo3temp/ folder and that they prevent new files from being generated! This is especially important to know if you are trying to set up image processing for the first time.

The problem is solved by clearing the files in the typo3temp/ folder. Also make sure you clear the database table "cache_pages".