trying to overwrite 'file', which is also in package '*', how to solve? [duplicate]
The problem is because the package is trying to override /usr/lib/librhythmbox-core.so.8.0.0 which is provided by another package.
librhythmbox-core7 is installed on your system, and you're trying to install librhythmbox-core8.
You need to manually remove librhythmbox-core7 before you can install librhythmbox-core8.
sudo dpkg --remove librhythmbox-core7
sudo apt-get install librhythmbox-core8
Also, inform the package maintainer about this.