Hello,
You can re-download the "StripeConnect HikaMarket" plugin to get the fix.
The issue is related to the fact that you do not have StripeConnect global credentials configured but the HikaMarket StripeConnect plugin is enabled.
Because the plugin can't find credentials, it returns a "false" instead of the Object for Stripe Connect API calls ; which result the error you got.
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.