Use apt-get to fix missing and broken packages

1. Update the repository index by executing the below command in Terminal:
$ sudo apt-get update

2. Next, execute the below command to clean out the local repository:
$ sudo apt-get clean

3. Execute the below command to remove all the unnecessary packages that are no longer needed:
$ sudo apt-get autoremove

The above command will display the unmet dependencies or broken package’s name.