Hello!
I've purchased VM invoice a few days ago, the mod is very nice, easy to use....but I have 2 major problems.
I can't edit my orders in VM invoice. I enter the edit mode, delete products, add products etc, everything is working. I give recalculate price, the price is recalculated correctly. When I hit the save button, I get redirected to the admin home page and the changes I've made are not saved. I have the same with the delete invoice feature. I select the invoices I want to delete, hit the delete selected invoices and the invoices are not removed, but I receive the "X invoices deleted" message. I am running on Joomla 2.5. 17 and VM 2.0.22.

I've got this error now when trying to change shipping method: Cannot store order shipment. TableVm2OrderShipment: :store failed
Unknown column 'virtuemart_shipmentmethod_id' in 'field list' SQL=UPDATE `mr2_virtuemart_shipment_plg_cargus` SET `virtuemart_order_id`='33',`virtuemart_shipmentmethod_id`='6',`shipment_name`='Livrare cu Cargus',`modified_on`='2014-01-16 19:01:07',`modified_by`='168' WHERE `id`='41'

Ok, I have investigated further....I have a shop with many products, and if there are more then 28 products in the order, everything I do after is not saved, and when I hit the save button, I am getting redirected to the admin home page.

Hello,

probably you will need to increase value of max_input_vars in PHP settings on your server.

I have it at 1000 :(

yes, this is default value. So now increase it as much as you think it will be enought. As you wrote 28 items=1000.