Hi,
The warning is not important.
Please forgot it and be sure that we will fix it. But it is not the source of your problem. Not at all.
The problem is coming from the view "category | selectparentlistin" which does not send the value of the parameter "id" when you browse a category.
At this moment, if you change a category and make a selection, the targeted element which should receive the value of the category id is lost.. And can't be updated.
I made the modifications in HikaShop but there are several points to modify and it won't be very easy to list them you here.
I will see with Nicolas to include the patch I made in a hotfix package for HikaShop 2.3.0
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.