The HorizenDesktopGUIWallet ( previously known as the ZENCASHWallet or the Swing wallet ) is also a full node wallet. As such, it cannot run at the same time that Sphere is running.
Even if you quit the HorizenDesktopGUIWallet it is possible that its zend process is still running.
Determine that no instance of zend is running. If so kill the zend process.
macOS- use Activity Manager
Windows- use Task Manager
Linux- use System Monitor or equivalent, or command line
