I tried to install crossover and after downloading the .deb from their website, I followed the steps as indicated when opening it with Ubuntu Software Centre:
On 64-bit flavors of Debian and some Ubuntu variants, first open a terminal and run
sudo dpkg --add-architecture i386 ; sudo apt-get update
Since I have Ubuntu 16.04 LTS 64 bit I perform the command.
But when copying and pasting that command into my terminal, it stopped at Fetched 535kb in 7sec and stalled there for about 20 minutes. I ended up closing it and tried to run both commands separately but after doing the
sudo apt-get update command it also stalls again after "Fetched XXKb in XXsec."
I restarted my computer and decided to run the software updater and it stays stuck at roughly 75% for hours.