Add-in palette address broken

[usolutionsTRFWW]

Hey, can you help me with using palette for displaying data from my api addon?
I get this

This site can’t be reachedThe webpage at file:///C:/%5CUsers/XXX/AppData/Roaming/Autodesk/Autodesk%20Fusion%20360/API/AddIns/Matsuura%20Sync%20addin%5Cpalette.html might be temporarily down or it may have moved permanently to a new web address.
ERR_INVALID_URL

I cant get it to be displayed correctly. 
My code to perform with palette

 palettes = ui.palettes
        palette = palettes.itemById('matsuuraInventoryPalette')
        
        if not palette:
            
            palette = palettes.add(
                'matsuuraInventoryPalette', 
                'Matsuura Inventory', 
                'palette.html', 
                True, True, True, 300, 400
            )
            palette.dockingState = adsk.core.PaletteDockingStates.PaletteDockStateRight
        
        palette.isVisible = True
        
      
        palette.sendInfoToHTML('updateInventory', json.dumps(results))​

I did double check if my file name for palette template is correct. and it is. However I am at a loss what did i do wrong.

[usolutionsTRFWW]

figured it out, need to force kill pallet object before call otherwise it holds cached page. even if it is error 404.