.. include:: /Includes.rst.txt

==========================
TYPO3 Exception 1478105826
==========================

.. include:: /If-you-encounter-this-exception.rst.txt

FlexForm location was not found, TYPO3 12.0
===========================================

..  code-block:: none

    Data structure file "EXT:my_extension/Configuration/FlexForms/NotExisting.xml" could not be resolved to an existing file
    
When opening a plugin in the backend and the referenced FlexForm is missing.

Solution
--------

Correct the path to the flexform in method :php:`ExtensionManagementUtility::addPiFlexFormValue()`, which is usually called in
:file:`EXT:my_extension/Configuration/TCA/Overrides/tt_content.php`.

Using `$_EXTKEY` in configuration files in TYPO3 v9 and above
==============================================================

This error can happen when using the variable :php:`$_EXTKEY` in a TCA
definition like :file:`Configuration/TCA/Overrides/tt_content.php` without
defining it. In TYPO3 versions before 8 the variable was automatically
defined.

Solution
--------

Replace all occurences of :php:`$_EXTKEY` with the extension's name or
define the variable locally.