Hi,
You need to check that you do not have the setting "no user assign" in your pack configuration.
www.hikashop.com/support/documentation/117-pack-edition.html
So the serial, while it will be created, will contain the link to the user who performed the sale.
Thanks to that, when you will perform an export in HikaSerial, you can have some user information.
If you want to add extra information, it will require a view override for the backend view : "serial / export"
The serial are also exported in the HikaShop order export, where you also have informations about the user (and the user custom fields).
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.