As Hikvision warranty is void in this case, you must rely on the dealer for any service, support, and warranty of the “gray market” product.
Restoring a “gray market” product to its original condition is a factory process and will result in a Chinese interface. Updating the firmware from this site can lead to several complications in those cameras, up to and including camera failure. If your camera has “CH” in the serial number, you are most likely using a “gray market” product. If you have purchased your Hikvision products from an online source or unauthorized distributor, they may not be compatible with the North American region’s firmware and are considered to be “gray market” product. Please be aware that Hikvision products are region-specific and regionally supported.