Hi,
Unfortunately like that, it will be difficult.
I know that I modified things in the past months and I also know that I already saw similar issue.
But the issue I remember where related to the way that HikaShop is checking some fields and, when HikaMarket stored a "real number", HikaShop was storing a string (with the number).
Now if you just have customized views in HikaMarket, you can update without issue.
You will have issues only if you have modified a core file without using an override.
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.