Why is my VNC cursor just a dot?

In VNC Viewer connection options, under mouse and keyboard settings, check the radio button for "Track remote cursor locally". It sounds like you have it set on "Don't show remote cursor".

When Launching UltraVNC use the command line argument "-normalcursor" to use the windows arrow.

Example: "vncviewer.exe -normalcursor"

I want to add some insights about Windows 10 VNC viewing. If you have trouble seeing a mouse cursor on a Windows 10 machine with no mouse attached, you can enable the "mouse control using Numpad keys" feature:

1. Open start menu.
2. Click the "Settings" cog
3. Click the "Ease of Access" menu item
4. Select "Mouse" in the left pane
5. Enable "Use numeric pad to move mouse around the screen"

This forces Windows to show a mouse cursor even with no physical mouse attached thus making your VNC life much easier. Bonus: you can actually see "Resize window" cursors on the windows edges!