Can't run Bitcoin Core 0.13.1 I have been running Bitcoin Core 0.12.1 for many months - using Ubuntu (Linux).  Decided to upgrade to SegWit version - 0.13.1 - today.  Downloaded and extracted the files (on my Ubuntu / Linux system) but can't get it to run - there is no executable file.  Can anyone help?  Many thanks, D
the ppa for ubuntu is https://launchpad.net/~bitcoin/+archive/ubuntu/bitcoin it shows the support of ubuntu 0.13.1

so you need to run 

sudo add-apt-repository ppa:bitcoin/bitcoin
sudo apt-get update



otherwise you can compile from source