looking at your ticket, it appears that this is due to upgrading PowerStore 4.x to PowerStore 4.5 but not uploading all of the updated files from the install/webassist folder.
In order to add the updated features such as shipping an tax rules, all of the files from the install/webassist folder must be updated on your server, it is not possible to have these updated functions work if all of the files are not updated.