expired token when set to not expire

Hi Greg,

   Thanks for the extra info, but as per earlier post I'm still unable to get an exception using any of those methods. In the earlier case, I had been testing it within a C#/.NET property change. I thought perhaps it might be a limitation with properties, so I wrote the code as a separate method which I then call at the appropriate place. Still not getting an exception. So I thought, well if I'm not getting an exception, then let's assign it to something and see what's in it - I got nothing. Not a result, not a null, nothing. No further code from the method executes after the first call to the Dropbox server (i.e. none of the writelines), so it seems I'm simply not getting any response at all from the server (until I try other calls later in my app and start getting the exception). This is consistent with my first observations of incorrect behaviour in that my app displays the username or "not logged in" as the case may be, but neither was appearing on screen (so again, looks like the call was hung). Not sure what the time-out period is on such a call? At this point I'm not sure what else I can do to check the token is valid, as nothing I've tried so far works. See below (in the meantime I shall read-up about what I need to do to implement refresh tokens)...

CODE

async Task<bool> TokenIsValid()
{
System.Diagnostics.Debug.WriteLine($"********************************** {nameof(TokenIsValid)} is checking token {DxToken}");
DxClient??=new DropboxClient(DxToken);
try {
    Account result=await DxClient.Users.GetCurrentAccountAsync();
    if (result!=null) {
        System.Diagnostics.Debug.WriteLine($"********************************** Name in result is {result.Name}");
    } else {
        System.Diagnostics.Debug.WriteLine($"********************************** Result is null!!");
    }
}
catch (Exception ex) {
    System.Diagnostics.Debug.WriteLine($"********************************** Exception in {nameof(TokenIsValid)}: {ex.Message}");
    return false;
}
System.Diagnostics.Debug.WriteLine($"********************************** Token is valid!");
return true;
}

OUTPUT (note that I have no further output from TokenIsValid after that first writeline)

********************************** DropboxService is being initialised
********************************** TokenIsValid is checking token sl.....
********************************** OnAuthorisedChanged is running with value Authorised:True
********************************** DropboxService has been initialised
Exception thrown: 'Dropbox.Api.AuthException' in Dropbox.Api.dll
********************************** UNHANDLED EXCEPTION! Details: Dropbox.Api.AuthException: expired_access_token/..
at Dropbox.Api.DropboxRequestHandler.RequestJsonString(String host, String routeName, String auth, RouteStyle routeStyle, String requestArg, Stream body); Request Id: b156453a19334fd0bfd773534492fe9c
Exception thrown: 'Dropbox.Api.AuthException' in System.Private.CoreLib.dll
********************************** UNHANDLED EXCEPTION! Details: Dropbox.Api.AuthException: expired_access_token/..
at Dropbox.Api.DropboxRequestHandler.RequestJsonString(String host, String routeName, String auth, RouteStyle routeStyle, String requestArg, Stream body)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw(); Request Id: b156453a19334fd0bfd773534492fe9c

thanks,

   Donald.