We are currently experiencing network disturbances at our supplier. We are investigating the cause of these problems and hope they will be resolved soon.

Update: Systems are now up and running again. There may still be some disturbances the next hours. We have talked to our supplier and they were having hardware problems which caused interruptions in several parts of their network. They have now replaced necessary hardware to prevent more problems.
We apologize the inconvenience and would also like to point out that we are now entering a new phase in testing our new servers. They will increase stability and robustness and we hope to switch to the new servers really soon.