Hello,
Right, thanks for your patience and your returns, we have now succeed to get a fix.
Follow me step by step to add the fix :
1. Go to tmpl folder, in YourWebsite\administrator\components\com_hikashop\views\product\tmpl
2. Find and open the export.php file
3. Around line 25, you can see this :
$columnsArray['categories_ordering'] = 'varchar';
$columnsArray['product_parent_id'] = 'varchar';
4. Just add immediately following this :
$columnsArray = 'varchar';
To have finally this :
$columnsArray['categories_ordering'] = 'varchar';
$columnsArray['product_parent_id'] = 'varchar';
$columnsArray['product_manufacturer_id'] = 'varchar';
And don't forget to make your returns to see if we can add this fix to our future release.
Regards