Is the HorizenDesktopGUIWallet Running? If you run the HorizenDesktopGUIWallet (formerly known as the Swing wallet) while Sphere is running, the message seen in Figure 1 will appear. If you run the Sphere while the HorizenDesktopGUIWallet is running, the message seen in Figure 2 will appear.
Quit HorizenDesktopGUIWallet
Quit Sphere
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
If there is a database directory (folder) within the sphereDatadir directory delete it. That is a symptom that zend did not shutdown properly.