Hi,
In the HikaMarket class product, for the function "frontSaveForm"
if($vendorClass->checkProductLimitation($vendor) !== true)
return false;
That code call the vendor class in order to know if the vendor have the right to create one more product.
And in the function "checkProductLimitation" you will find the line
$vendor_limitation = $config->vendorget($vendor, 'product_limitation', 0);
which will read the value in the vendor accesses for the current vendor.
So it requires some more deep tests in order to reproduce the issue and find the right fix.
Regards,