Important: #107848 - DataHandler properties userid and admin removed 

Description 

The internal properties \TYPO3\CMS\Core\DataHandling\DataHandler::$userid and \TYPO3\CMS\Core\DataHandling\DataHandler::$admin have been removed.

These properties contained information that is already available through the BE_USER property and were therefore redundant.

Impact 

Accessing these properties directly will result in a fatal PHP error.

Affected Installations 

All installations with extensions that access the following properties:

• \TYPO3\CMS\Core\DataHandling\DataHandler::$userid
• \TYPO3\CMS\Core\DataHandling\DataHandler::$admin

While these properties were marked as @internal, they have been commonly used by extensions, especially the $admin property.

Migration 

Replace any usage of these properties with the appropriate methods from the BE_USER property:

For `$userid`:

// Before:
$userId = $dataHandler->userid;

// After:
$userId = $dataHandler->BE_USER->getUserId();

For `$admin`:

// Before:
if ($dataHandler->admin) {
    // do something
}

// After:
if ($dataHandler->BE_USER->isAdmin()) {
    // do something
}