would it be possible that in the export script
galleryimagelist
should read gallery_imagelist
as this is the same name used in the pivotx extension
http://extensions.pivotx.net/entry/39/gallery<!-- Warning! Extrafields key not found! galleryimagelist. Value: 2016-05/skipnationals2016.jpg
2016-05/nationals-banner-30x96-1024x320.jpg######
2016-05/img_0607.jpg######
Extension inactive? Check code to find fields. -->
would it also be possible that the following goes wrong with a image field export that only exports a number instead of the filename
<wp:postmeta>
<wp:meta_key>pivx_extrafield_achtergrond</wp:meta_key>
<wp:meta_value><![CDATA[3632]]></wp:meta_value>
</wp:postmeta>
<wp:postmeta>
<wp:meta_key>_pivx_extrafield_achtergrond</wp:meta_key>
<wp:meta_value><![CDATA[field_5467c15f00005]]></wp:meta_value>
</wp:postmeta>