This error usually means that the network connection was lost. This could occur due to large amounts of data to sync during the log in and the connection simply times out (think about trying to send an email with extremely large attachments - sometimes, it times out before it can send it all).
You could also get this message if the internet connection happens to be going in and out (think about when you hit a dead spot in cellular service - calls are dropped, internet searches can't complete, etc).
Another reason could just be a very slow connection due to high traffic times of days or strength of signal.
When you get the 1005 error, check to see what kind of internet response you are getting in general. They should correlate. If this doesn't seem to be the culprit, then please submit a ticket to technical support so that we can troubleshoot the issue with you.