Thank you for your suggestion.
I have tried to update the MC22 following the instructions given in "Step 4 - Updating Media Center 22".
Therefore, I typed in the terminal the following command:
sudo apt-get update && sudo apt-get dist-upgrade
I received the below error messages and MC22 did not update.
I'm not a Linux expert and your help would be much appreciated.
The error messages shown in the terminal following the above commands are:
W: There is no public key available for the following key IDs:
1397B... (I deleted the rest of this ID in case of personal info?)
W: Failed to fetch
http://dl.google.com/linux/chrome/deb/dists/stable/Release Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)
E: Some index files failed to download. They have been ignored, or old ones used instead.