Finally i installed Ubuntu 17.10 and upgraded it to 18.04, it works. Install 17.10 open terminal and enter following commands..
$ sudo apt update $ sudo apt upgrade $ sudo apt dist-upgrade
$ sudo apt install update-manager-core $ sudo do-release-upgrade -d
Finally i installed Ubuntu 17.10 and upgraded it to 18.04, it works.
Install 17.10 open terminal and enter following commands..
$ sudo apt update
$ sudo apt upgrade
$ sudo apt dist-upgrade
$ sudo apt install update-manager-core
$ sudo do-release-upgrade -d