Managing Extensions - Legacy Guide

Installing an Extension using the Extension Manager

In the backend:

  1. Go to “ADMIN TOOLS” > “Extensions”

  2. In the Docheader, select “Get Extensions”

  3. Click “Update now”

    The button is on the top right.

  4. Enter the name of the extension in the search field

  5. Click on “Go”

  6. Click on the Action icon on the left for the extension:

    “Import and Install”

    Now the extension is installed, but not activated. To activate:

  7. Choose “Installed Extensions” in the Docheader

  8. Click on the icon with a “+” sign for your extension in the “A/D” column.

Uninstall an Extension Without Composer

If you installed TYPO3 via composer you should uninstall Extensions via composer.

Check Dependencies

First find out, which other extensions and functions of your TYPO3 installation are dependent on the extension you want to uninstall. You can find out about the dependencies by checking the Extension Repository. Look for the extension you want to uninstall and the others you have installed. Read in each extensions manual the sections ‘Dependencies’ and ‘Reverse dependencies’.

Check whether any referrals have been made to the extension in any setup, config or other TypoScript files. Check if you included a plugin from the extension in your web site. Think of the results of removing them and finally do it.

If you are working locally or on a test server you might as well try to uninstall the extension. The Extension Manager warns you about dependencies that are written in an extensions ext_emconf.php constraints section. Note however that you depend on the extensions developers faithfully noting all dependencies in this config file.

If you get an exception and can’t even access the Extension Manager anymore because of it, you can uninstall / install extensions manually with PackageStates.php as a last resort, see Uninstalling an Extension Manually

Tip

Be sure not to uninstall extensions by trial and error on production systems, especially not under time pressure.

Uninstall / Deactivate Extension via TYPO3 Backend

../_images/UninstallExtension.png

Select “Deactivate” in Extension Manager

Log into the TYPO3 Backend and open the Extension Manager (‘Ext Manager’). From the menu choose ‘Install extensions’. You get an overview about installed extensions.

On the left side you see an icon, which shows the status of each extension, and what you can do:

  • Extension Install Icon with plus sign: The extension is not installed. (Click once to install)
  • Extension Uninstall Icon with minus sign: The extension is installed and running. (Click once to uninstall)

Next to the extension you want to uninstall click on Extension UnInstall Icon. After some seconds the icon changes to the grey Extension Install Icon.

Remove an Extension via the TYPO3 Backend

After successfully uninstalling an extension via the Extension Manager you can permanently remove the extension by clicking on the waste-basket symbol “Remove” beside the extensions entry in the Extension Manager.

Uninstalling an Extension Manually

At times an extension causes a problem and the TYPO3 Backend can not be opened anymore due to it. In such a case the extension can be uninstalled manually. This is not common practise but a last resort.

Since LTS8 this can be done by removing the extensions configuration from the file PackageStates.php

  1. Open the file typo3conf/PackageStates.php

  2. Search for your ext_key in the array.

    'ext_key' => [
          'packagePath' => 'typo3conf/ext/ext_key/',
      ],
    ...
    
  3. Remove the entry.

Removing an Extension Manually

Removing an extension manually is not common practice and should only be done as a last resort. You should only remove an extension that you uninstalled successfully. Make a backup first. Then you can permanently remove an extension by removing its folder at typo3conf/ext/[extensionname]. The corresponding database tables can be removed in the Install Tool -> Important Actions -> Database analyzer -> Compare current database with specification.

Additional Information

The following is independent of whether you install with Composer or without.

Find out the Extension Key for an Extension

Again, go to the Extension Repository, and search for the extension.

The extension key is listed on the top. For the extension news, the extension key is news.

You can also see the extension key in your file system in the directory public/typo3conf/ext/. The directory name of the extension is the same as the extension key.