Welcome to the Magix user to user forums, so not a contact for any Magix staff, sorry.
The problem you are seeing could be caused by a fault at the Magix server, I think. Assuming your Update Service is still current and that you are, therefore, still allowed to access the online catalogue, I think you need to email infoservice@magix.net and request their help, quoting the error message in full. I doubt whether any other user can provide help with this particular problem.
For what it's worth I am having the same problem. I uninstalled and reinstalled Xara and the issue was resolved - for a short while. Now, the problem has returned.
in addition to the above comments, once you get connected back to the Online Gallery, I would advise you to download all of the Online content to your PC, this will save issues with connectivity.