Thank you. I switched to this fork. To install it:
Download https://get.popcorntime.sh/build/Popcorn-Time-0.3.9-Linux-64.tar.xz
Uncompress it (you can right click on it with Trisquel's default file
manager);
Optionally move the uncompressed directory wherever you want (and/or rename
it);
With the "New Item" button of "Main Menu" (in the "System settings"), create
a launcher (in the "Category" of your choice, e.g., "Sound & Video"),
specifying the path to the "Popcorn-Time" binary (the the uncompressed
directory) as a "Command", any "Name" you want (e.g., "Popcorn Time"), any
"Comment" you want (e.g., "Watch Movies and TV Shows instantly") and any icon
yu want (e.g., src/app/images/popcorntime.ico in the uncompressed directory).