Tanx jac0b,
But I have already followed one of the links u forwarded earlier and did these steps to solve the problem.
1. Open the Adept Manager by going to KMenu -> System -> Adept Manager (Manage Packages)
2. In Adept, go to Adept -> Manage Repositories
3. Enable the "Recommended updates" and "Pre-released updates" repository, close and reload
4. If your system is up to date, the upgrade wizard will be offered after you click "Fetch Updates" via the "Version Upgrade" button, else..
1. Press the Full Upgrade button
2. Press the Apply Changes button
3. Once the packages are installed, exit the Adept Manager (Adept -> Quit)
4. Repeat the initial steps (1 - 3)
Especially by enabling the "pre-released updates" repository, it works well.
Besides, it used to ask me for the installation CD everytime I try to install a software from the Adept Installer. But, by changing the Software source from cdrom to
http://archive.canonical.com/ubuntu gusty partner, I redirect the installation from the online archive rather than from the CD. This can be done in the Adept manager Manage Repository menu, Third-Party Software tab.
Enjoy the free operating enviroment