Apps タブに「ダウンロードエラー」が表示される。

Is it a creative Cloud for teams license you have?

The administrator doing the package has the ability to allow non administrators to install software via the CC app. You should contact your administrator on this.

If it is a standard single user CC license, you should get administrator privileges before you can install any software.It may, however, be possible for an administrator, to mark the CC app to start with the administrator privilege.