Why does KF2 freeze when the boss dies or when I die?

According to the guide, the game connects to a Google time server during the end-of-match calculation; where that server is blocked (as in mainland China), the connection hangs. Manually mapping the NTP hostnames in the hosts file fixes it.

How can I test the fix?

Play solo and die on purpose. If it does not freeze, the fix worked. If it works solo but not in multiplayer, ask the server owner for the server's NTP address.

Fixes & Performance

KF2 Freeze After Killing the Boss or Dying: Hosts File NTP Fix

This short guide, originally in Chinese, is a fix for the freeze that some players get when the boss dies or when they die in Killing Floor 2. The author's explanation is that, during the settlement at the end of a match or on death, the game contacts a Google time server, and because that server is blocked in the player's region the game stalls. The cure is to map the time-server hostnames to IP addresses by hand. For other connection problems see connection lag and disconnect fixes.

The fix

Open the hosts file at C:\Windows\System32\drivers\etc\hosts (edit as administrator) and add the following lines:

114.118.7.161 time1.cloud.tencent.com
193.228.143.13 time1.cloud.tencent.com
203.107.6.88 time1.cloud.tencent.com
182.92.12.11 time1.cloud.tencent.com
182.92.12.11 time.google.com
114.118.7.161 time.google.com
193.228.143.13 time.google.com
203.107.6.88 time.google.com

Note: the original list repeats 182.92.12.11 time.google.com; the author's text lists each address for both hostnames. These IPs belong to a regional NTP setup and are only appropriate for the situation the author describes.

How to test

Start a single-player game and die on purpose. If there is no freeze, the fix is working. Every server uses a different NTP time-server IP: if the fix works in single player but not in multiplayer, ask the server owner for their NTP address and add it in the same way.

Safety

Editing the hosts file redirects the names you list for the whole system, so remove the lines if you later run into time-sync problems in other programs, and keep a backup of the original file.

FAQ

Why does KF2 freeze when the boss dies or when I die?: According to the guide, the game connects to a Google time server during the end-of-match calculation; where that server is blocked (as in mainland China), the connection hangs. Manually mapping the NTP hostnames in the hosts file fixes it.
How can I test the fix?: Play solo and die on purpose. If it does not freeze, the fix worked. If it works solo but not in multiplayer, ask the server owner for the server's NTP address.