u need to unmount internal storage first b4 attempt to install Teamviewer...
to unmount internal storage:
1) goto Settings
2) goto Complete Settings
3) under Device, click Storage
4) scroll down until u see Unmount shared storage option, click on it to unmount
5) install Teamviewer
5) mount back shared storage by following Step 1 to Step 4, but click on Mount shared storage option this time...