You can check the list of all grids you’ve authorized to use the account on the Gloebit website, by clicking on your name and selecting “Manage Access” in the drop-down menu. Make sure that those grids are authorized and showing. When transactions fail latency can also cause it. Make sure when you are buying the item you allow plenty of time for the transaction to complete. It also could be the grids you are buying from have issues on their end. It is all working okay on my grid, and the grids that I have authorized payment all seem to be working too.