Hi,
We are already aware of the problem, there iis already a thread which talk about and we already found the solution.
The problem is coming from : Falang 1.4.2
The problem is that HikaShop call a function "lastInsertId" in order to get the order_id just created in the database but for the unknown reason, the function does not return the inserted id anymore ; due to falang.
Please deactivate the "falang driver" system plugin and it will work again.
For more details, please see with the Falang support.
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.