TYPO3 Core

If a form contains a multi-select, the user is not able to type text in any textfield, since the validation jumps to the multi-select after each button press.

TCA:

'validfor' => array(
            ...
            'config' => array(
                'type' => 'select',
                'renderType' => 'selectSingleBox',
                'foreign_table' => 'tx_...',
                'minitems' => 0,
                'maxitems' => 999,
                'MM' => 'tx_..._mm',
                'size' => '3'
            )
        ),