echo "deb https://apt.syncthing.net/ syncthing stable" | sudo tee /etc/apt/sources.list.d/syncthing.list
nigel@nigel-VirtualBox:~$ sudo apt-get install apt-transport-https
Reading package lists... Done
Building dependency tree
Reading state information... Done
apt-transport-https is already the newest version (1.6.12ubuntu0.1).
The following packages were automatically installed and are no longer required:
efibootmgr libegl1-mesa libfwup1 libwayland-egl1-mesa
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
N: Ignoring file 'syncthing.net' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension
I thought I made it very very clear that I did not create the file syncthing.net . I followed the install using cut and paste.I wrote that too.
I have no idea why the file was created and I need to know why. looking at my history file there is nothing there that would create the file.