I cancelled my FlightPlan to change to earlier departure due to WX. In trying to submit the plan the window says "requesting credit count" and has greyed out the continue button, I had one credit remaining but even bought another 20 but can't resolve it. Any clues?

It rather sounds like you were experiencing a general network issue, particularly as GAR functionality (which as you know is not provided by us, rather by OnlineGAR.com) seemed to be playing up as well. However I encourage you to engage with support directly, who will ask you for specific error messages etc, so we can get to the bottom of it.