here is the solution the pro support came up with :
We have been preforming some maintenance to our login system and are currently working on a fix for this bug. So far the most successful solution has been to log of your Google account out by selecting the icon at the bottom right side of the SketchUp drawing window (see attached photo). Once you are logged out, log back in and then try to access the Extension or 3D Warehouse again and it should allow you to log into your account.
this worked to resolve issue immediately on all copies and versions