fileTree select doesn't save

[marcroelans]

Contao: 4.4.46
Contao Manager: 1.2.3.

The file selection via the fileTree type does not work: The server returned a "400 Bad Request".

'images' => [
        'label' => &$GLOBALS['TL_LANG']['tl_nm_news']['images'],
        'exclude' => true,
        'inputType' => 'multiColumnWizard',
        'eval' => [
          'columnFields' => [
            'image' => [
              'label' => ['Bild'],
              'exclude' => true,
              'inputType' => 'fileTree',
              'eval' => [
                'filesOnly' => true,
                'fieldType' => 'radio',
              ]
            ]
          ]
        ],
        'sql' => 'blob NULL'
      ],

[zonky2]

@marcroelans what ist the different to issue https://github.com/menatwork/contao-multicolumnwizard-bundle/issues/51 ?