These freezes, for me, happen in multiplayer. Game/Session (Host) PC, 3570k/16GB ram/GTX 1060 (6gb vram)/Win10, (Non-Host) PC 4570k/8gb ram/GTX 970/Win 7.

Things I have tried-
Verified Files for both Host and Non-Host PC
Updated Nvidia Drivers on Both Host and Non-Host PC (466.11)
Port Forward port 18000
Network Firewall ON & OFF

The following are the instances that caused a complete game freeze ranging from 10-15 seconds each time:

-Editing or using Propaganda in Newspaper (Host/Non-Host)

-Adding first Silo to Pig Farm [possible Quest Completion?] (Host)

-Freeze after Completing a Puzzle Quest (Non-Host)

-Adding 'Silo' to Pig Farm [For Quest] (Non-Host)

-Adding first 'Sailing Shipyard' (Host)

-Initiating a quest 'Literary Contacts'. (Non Host)

-Freeze opening Quest Log (Non Host)

-Freeze after cancelling a quest (Host)

-Getting Achievement 'Gold Digger' (Non-Host)

-Adding 'Silo' to 'Cattle Farm' (Non-Host)

-Accepting quests, 'Shadow Puppets 1' (Host)

-Manual ship to Harbour item transfer, (Non Host)

-Starting New World Expedition or reviewing Expedition steps thereafter (Non Host)

Non-Host can review a newspaper and the game will not freeze until the instant a change is made; this happens the instant a edit is dropped into the paper. If Non-Host waits for a freeze to end after editing the newspaper and then choses to drop another edit into the paper a freeze will happen after ever edit.