Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend

This error message indicates that the dpkg package management system is currently in use and unable to obtain the lock required to complete the operation you're trying to perform.

Here are a few possible solutions to resolve the issue:

Check for other package managers: Make sure that there are no other package managers, such as apt-get or Software Center, running simultaneously. They can conflict with dpkg and cause the lock error. Close any other package managers before attempting the operation again.
Wait for the lock to be released: Another process might be using the dpkg lock. Wait for a few minutes, as the lock will be automatically released once the other process finishes its task. Then, try the operation again.
Remove the lock file: If the lock is not being released, you can manually remove the lock file using the following command:
```
sudo rm /var/lib/dpkg/lock-frontend
```
Verify no running processes: Check if any dpkg or apt processes are still running. Run the following command to verify:
```
ps aux | grep -i apt
```
If there are any processes listed, terminate them using the following command (replace the process ID with the actual ID of the process using the dpkg/lock-frontend):
```
sudo kill <process_ID>
```
Restart your system: Restarting the system can often help resolve any lingering issues causing the lock error. After the reboot, try to perform the operation again.

If the issue persists, you might want to investigate if there are any underlying problems with your system's package management system. In rare cases, it could indicate a system corruption, which may require further troubleshooting or even a system reinstallation.