Im not exactly sure what wireguard doing to create virtual network adapters in windows, but it's more looks like it can't handle deletion of them properly.
This issue easy to reproduce:
  1. Create wireguard's tunnels.
  2. Connect tunnel, disconnect and remove it.
  3. Repeat it multiple times.
Windows registry will be full of wrong records of these non-existed network connections.
And now try to open Task Scheduler and click on "Create task..." it will crash with log:

в Microsoft.Windows.ManagementUI.CombinedControls.INetwork.GetName()
  в Microsoft.Windows.ManagementUI.CombinedControls.UINetwork.GetUINetwork(INetwork network)
  в Microsoft.Windows.ManagementUI.CombinedControls.NetworkListManager.GetNetworkList()
  в Microsoft.Windows.ManagementUI.CombinedControls.ControlTaskConditions.PopulateNetworkComboBox()
  в Microsoft.Windows.ManagementUI.CombinedControls.ControlTaskConditions.InitializeConditions()
  в Microsoft.Windows.ManagementUI.CombinedControls.EditTaskDialog.InitializeView()
  в Microsoft.Windows.ManagementUI.CombinedControls.EditTaskDialog.Initialize(UITaskFolder folder, String taskName, String title, UserChoice userAction, BaseResultsControl inOwnerView, String inXmlText)
  в Microsoft.Windows.ManagementUI.CombinedControls.BaseResultsControl.CreateTask(UITaskFolder folder, String initialTaskName, String taskXml)
  в System.Windows.Forms.MenuItem.OnClick(EventArgs e)
  в System.Windows.Forms.MenuItem.MenuItemData.Execute()
  в System.Windows.Forms.Command.Invoke()
  в System.Windows.Forms.Control.WmCommand(Message& m)
  в System.Windows.Forms.Control.WndProc(Message& m)
  в System.Windows.Forms.ListView.WndProc(Message& m)
  в System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

So ive googled solution https://answers.microsoft.com/en-us/windows/forum/all/task-scheduler-crashed/5acab7c5-eb79-48c8-876d-ade321565953?auth=1 (Programatix message)

To resolve the problem,
    Run regedit
    Go to HKLM\Software\Microsoft\Windows NT\CurrentVersion\NetworkList
    Delete everything under the following path,
        Nla->Cache
        Nla->IntranetEnabled
        Nla->Wireless
        Profiles
        Signatures->Managed
        Signatures->Unmanaged
    Reboot

And it actually helps.
Can wireguard just properly handle this "issue" on his own and do not break Task Scheduler application?