Image upload doesn't work with new field

[p380]

I want to have an additional image field in the form. In the form I extended a new custom field for the image.
Uploading an image works in an additional field, as well as in the default image field (image).

But when I remove the image from the 'image' field and want to add a new image I get an error.

In2code\Femanager\DataProcessor\ImageManipulation::getNewImageName(): Argument #1 ($fileItem) must be of type array, string given

Probably because the image is added in the custom field?
If I remove this image from the custom field, then uploading the image to the default 'image' field works.

Regards