Sub-orders can't be deleted

I'm trying to delete some tests orders in backend but I got this message: "Sub-orders [2, 4, 6] can't be deleted, please delete their parents".

What should I do?

Ok, where can I find parent orders? In my orders list in back-end, if I filter to "All vendors" I see only 3 items and if I try delete them I got that message: "Sub-orders [2, 4, 6] can't be deleted, please delete their parents".

So I set filter to "No vendors" and I delete all the orders that it show me, the are correctly deleted. Now I set back filter to "All vendors" and I still see all vendors orders and I cannot delete them, same message: "Sub-orders [2, 4, 6] can't be deleted, please delete their parents".

What's wrong?

ADD to previous post.

Now, when I click on the order menu link I go this error: 500 SQL=SELECT a.* FROM jos_hikamarket_vendor AS a WHERE a.vendor_id IN ()

Thanks Jerome. I think now it's better I wait for your new package with new fixed issues and improvements so I can install it on a fresh J! and Hikashop installation. Maybe during tests something went wrong.

Hope you'll send me soon the new package so I'll go on testing.

Best regards