Throughout the past few days or so, confirmed to also exist on 0.14.14 as of 11PM EST 10/14/2016
Computer Info
Windows 7 Pro 64-bit SP1
Factorio 0.14.14

Bug Description
While playing on a vanilla client/server, a dialog appears saying "Server is not responding"

Other players on the server do not see anything wrong during this time.
When the progress bar gets to the end, the player is dropped and is given the option to reconnect.
At this time other players are told the player has left the game.
Steps to Reproduce
I have been unable to reproduce the bug in a reliable fashion.
Troubleshooting/Testing Steps Attempted
Attempted to play on a fresh multiplayer server with an unmodified control.lua (Non custom scenario)
Within minutes of a fresh start server someone else hosted the bug occurred again as described earlier
Reconnected and was able to play with no issues for another hour before it occurred again.
During this time I was also running PingPlotter to make sure it wasn't a network issue.
Based on the results from that, my network connection was stable during the times drops occurred.
The factorio-current.log is attached for reference.
Thanks!