Troubleshooting V650 sync in FlowSync (Windows)

Please note, that when you plug your V650 into your computer it may take some time to establish the connection between your V650 and the computer. Be patient and wait for the sync to start.

If V650 sync doesn’t start in FlowSync or you get a “Connection error. Connection to Polar product lost.” error message, try the following steps one at a time.

Make sure that your computer operating system supports V650

See The technical requirements for using FlowSync for compatible operating systems.

Make sure you are following the syncing instructions

See How do I sync my V650 with Flow web service (Windows) for detailed syncing instructions.

Make sure the USB cable is connected to V650 properly

  • If your V650 doesn’t charge properly, or if it doesn’t connect to FlowSync, remove and replug the USB cable.
  • Always connect your V650 directly to your computer’s USB port. Do not connect it via USB hub, computer docking station or USB extension cable.
  • Try the other USB port(s).

Be patient and wait for the sync to start.

Restart FlowSync

Close FlowSync by right-clicking/secondary clicking the icon on your computer taskbar and choosing Close. Then restart FlowSync from your computer desktop icon.

Restart your computer

Restart your computer while keeping the V650 connected to the USB port. V650 must be turned on and in the main view.

Restart V650

Press the side button and choose Turn off your V650, then restart the V650 by pressing and holding the side button. After the restart keep the V650 in the main view and be patient and wait for the sync to start.

Try syncing with another micro-USB cable if you have one.


Enable Javascript and cookies in your browser

Javascript and cookies need to be enabled for the connection to work. Usually they are enabled by default. See your browser's help for further instructions.

Make sure Bonjour Service is running

  • Windows 7: Go to StartControl PanelAdministrative ToolsServices. Make sure Bonjour Service is running and its status is Started.
    Windows 8 and 10: Use Search Window to open Services application.
  • Click Bonjour Service and Start the service or click Restart the service.

  • When you enable Bonjour Service, the mDNSResponder.exe process or Bonjour Service (Windows 10) appears on the list of running processes in Task Manager. The mDNSResponder.exe process belongs to the Bonjour for Windows service.

Make sure Polar FlowSync software and Bonjour service are allowed to pass through the firewall without restrictions

See below an example from F-Secure. If IPv6 traffic filtering option is set to Block, V650 connection can’t be established.

Also check that Bonjour Service or FlowSync aren’t blocked by any antivirus software.

Below you can see an example from F-secure.

You can temporarily disable the antivirus software and firewall and try syncing your V650 to make sure the antivirus software and firewall are not the root cause for the problem.

Make sure that other running software isn’t blocking the sync

  1. Close all other running software, including the ones that start automatically when you start your computer.
    Windows 8 and 10: Choose Task managerStartup. Disable all other software except for FlowSync
    Windows 7: Choose StartSearch programs and files. Write msconfig. Choose StartUp tab and click the Disable all button. Disable all programs except for FlowSync. Click OKRestart.
  2. Restart your computer and make sure Apple Bonjour service is still running: Go to Control PanelAdministrative ToolsServices. Click Bonjour service and Restart the service. (click Start if the service is not running). Try syncing your V650 again.

Make sure your computer recognizes your V650 correctly

Reconnect your V650 with the USB cable. Connect your V650 directly to your computer without using a USB Hub, computer docking station or USB extension cable.

Unplug all other USB devices from your computer.

Restart your computer keeping your V650 connected to the computer.

Retry syncing.

Check that V650 is shown on your computer as Remote NDIS based Interned Sharing Device.

  • Windows 7: Go to StartControl PanelDevice ManagerNetwork adapters.
  • Windows 8 and 10: Use Search Window to open Device Manager.
  • Your V650 is shown as Remote NDIS based Internet Sharing Device.


    Remote NDIS driver is automatically included in the Windows operating system. If the driver is not found or correctly installed, you'll see an exclamation mark.


    If there’s no sign that V650 is connected, click Scan for hardware changes.


    To manually update the driver, right click/secondary click the device and choose Update Driver Software.


    Choose Browse my computer for driver software.


    Next choose Let me pick from a list of device drivers on my computer.


    In the Select Network Adapter window, choose Microsoft Corporation and Remote NDIS based Internet Sharing Device. Click Next to finalize the driver update.


    After the driver update, your V650 should be recognized and the sync should proceed.

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