Hi,
If you put a vendor restriction, you can just specify one single vendor.
If the restriction is "0" (or empty) so there is no vendor restriction.
If the restriction is "1", it will be your main vendor (your store).
But we don't support the multiple vendors in this field for one reason : In a future release of HikaMarket, vendor will be able to create/modify their shipping methods.
That's why the "vendor option" in the shipping configuration just allow to select one single vendor.
For what I saw in your website. I didn't have to possibility to have the shipping available for one single vendor.
I got the message "cart weight is to low" or "cart weight is too big".
So, I really think that it is a weight restriction problem.
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.