Hi,
I moved your topic in the Russian section of our forum.
If you want some help from the HikaShop support team, please create a new thread in the HikaShop forum but in English.
(The HikaShop support team is not notified of message from language section that we do not read/understand/support)
There might have some misconfiguration in HikaShop or some troubles with the SEF.
The url "yourwebsite/updatecart" is not a valid one because it does not contain any Joomla menu to call HikaShop.
It can be a misconfiguration for the targeted menu (and result a wrong url) or a problem with the SEF.
You can deactivate the SEF in order to make some tests.
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.