In case in-client upgrade is not working...

There is a bug in certain versions of DW Spectrum 4.0 which prevents the in-client upgrade function from working correctly on Ubuntu. 
The client will update successfully but the server will be stuck with the status “Installing…” and never finish.

In order to fix this you will need to manually upgrade your version of DW Spectrum to 4.0.0.30434 or newer:

Download the server .deb file of a version with the fix.

Open the terminal and navigate to the directory where you placed the .deb file (usually $HOME/Downloads) 

   cd ~/Downloads

and install it using the following command: 

   sudo dpkg -i <file_name of downloaded .deb file>

   Example: sudo dpkg -i dwspectrum-server-4.0.0.30434-linux64.deb

[Optional] After running the above command the update will install and the DW Spectrum mediaServer will be restarted. 
In case you need to install any missing dependencies you can also run the following command:

   sudo apt-get install -f