I followed the recommendations in the following Q&A to get my phone to work with Ubuntu:
How to connect Nokia Lumia 520 to Ubuntu 12.04
Unfortunately the installation failed for me. When updating I get the following error:
W: Failed to fetch http://ppa.launchpad.net/langdalepl/gvfs-mtp/ubuntu/dists/trusty/main/binary-amd64/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/langdalepl/gvfs-mtp/ubuntu/dists/trusty/main/binary-i386/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
How can I get this PPA to work? Is there any other method to access the files and folders on my phone?