Asus zenfone 5 lite Serial number registration error

[Rizwan7869750]

Model Name: ASUS ZENFONE 5 LITE
NOT rooted.
I bought my Asus Zenfone 5 Lite 1.5 years ago and dont show any update after cheking Updats again and again.
when I decide to registard My Product then show "Invalid Serial Number"
how to make Valid ?
Give Any Solution without asking me to go serves Center.

[Christine_ASUS]

Hi Rizwan7869750
Thank you for your asking. Each official device has its own Serial Number.
1. Did you purchase the device from ASUS authorized channel with first hand?
2. Have you ever repaired your motherboard in the unauthorized repair center?
3. Please check your inbox and provide me the screenshot of your SN and IMEI for further checking.