phone backup failed

Hello friends,

I am trying to backup my iPhone 8 using iTunes onto my Mac, but persistently getting the following error.

I read the support pages which asked me to access Device Backups under ITunes preferences and delete old backups. But when I access the desired page, there are no backups listed.

What am I doing wrong here ?

Both Device & my Mac are on latest available versions.

Device: iPhone 8 on 12.4

Mac: Mojave 10.14.5.

I have tried backing up to iCloud instead, but getting same error on that option too.

Any help would be greatly appreciated.