Please see sticky at top of forum about how to attach a log.
Here is a log, although this is very obviously a server side issue judging by the amount of users it is currently affecting.
Logs also agree:
[16:39:12.600 D] Mesh file received could not be verified. (Expansion01_19_28.etm)
[16:39:12.600 N] No data for Expansion01_19_28.etm
[16:39:12.600 D] Activity: Loading Tile/s
[16:39:12.600 D] Activity: Downloading Mesh...
[16:39:15.426 D] Mesh file received could not be verified. (Expansion01_19_28.etm)
[16:39:15.426 N] No data for Expansion01_19_28.etm
[16:39:15.426 D] Activity: Loading Tile/s
[16:39:15.426 D] Activity: Downloading Mesh...
[16:39:15.794 D] Exception when attempting to download Expansion01_20_27: System.ServiceModel.CommunicationException: The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:00:29.8179896'. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.ServiceModel.Channels.SocketConnection.ReadCore(Byte[] buffer, Int32 offset, Int32 size, TimeSpan timeout, Boolean closing)
--- End of inner exception stack trace ---