You will probably need to do this:
You need to upgrade to 2.9.3 for syncing to work properly. In Tails it's hard (near impossible?) to upgrade using normal method so your best, easiest way is to download the tar archive from electrum.org and run portable. Here's a 123...
1. Download from electrum.org - be sure correct https site.
2. Open terminal, change to Persistent folder (or wherever if no persistence but then you'd have to download each session): "cd Persistent"
3. Unarchive the tar you downloaded: "tar -xzvf Electrum-2.9.3.tar.gz"
4. Change into that new folder: "cd Electrum-2.9.3"
5. Run it. If you have Electrum persistent then run normally, eg "python electrum" and it will use your normal wallet. If not then use the -P option for "portable" and you'd need to copy the wallet file in or restore each session (since not persistent): "python electrum -P"
This downloaded copy is independent of the 2.7.9 installed and doesn't touch that but since it's not working any more you may want to create a dekstop icon for this copy. Basically copy the electrum.desktop file from the current folder to your ~/Desktop folder and then edit it to have correct paths to exec. But you also need to set persistence for Dotfiles to persist the icon - more steps but ask if you really need that.
Source:
https://www.reddit.com/r/Electrum/comments/78p9dz/electrum_in_running_in_tails_os_does_not/dovztij
