Adobe CC 2015 Installation Stuck at 42%

You can try below steps:

1) Trash Adobe apps from Applications .

2) Trash below mentioned folders from Applications > Utilities.

• Adobe Creative Cloud
• Adobe Application Manager
• Adobe Utilities.
• Adobe Installers.

3) Trash Adobe folders from below locations.

Adobe folders will be present inside Application Support folder.

• ~/Library/Application Support/ [ User Library ]
• /Library/Application Support/ [ System Library ]

Then Run Adobe Cleaner tool and select Clean All option .
Download Adobe Cleaner Tools Here

Then reinstall Adobe Creative Cloud app and try to install your Adobe products again.

Enjoy