Hi,
Without knowing the context we cannot provide you any useful answer.
Now, the "modifyOrder" function is working perfectly fine because that function is used by all the HikaShop plugins.
If you give the function an order id, it will update the order in the database (using the save function and it will call the triggers).
If you give the function an order object, it will update the object and let you perform the save afterwards.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.