How do I get a vault crate that did not show up?

Right after the vault meter fills and the game awards a crate, open the Steam overlay with Shift+Tab quickly and go to the in-game inventory. The crate should then pop out.

Which file should I allow through the firewall?

The Killing Floor 2 executable in the Binaries\Win64 folder of the game, for example C:\Program Files (x86)\Steam\steamapps\common\killingfloor2\Binaries\Win64.

Why would a VPN help?

The author found a report that some countries, such as Russia and Indonesia, block connections to the reward system. He says this stops weekly or seasonal rewards and vault crates, but not random drops.

Fixes & Performance

KF2 Missing Vault Crate Fix: Shift+Tab, Firewall and VPN

Players sometimes finish the vault meter or a weekly and get no reward in Killing Floor 2. This guide gathers three methods that the author tried. For a related crate topic see USB crate will not open.

Method 1: Shift+Tab right after the crate

This is the best-known fix. As soon as you receive a vault crate, press Shift+Tab very fast to open the overlay, then go to the in-game inventory screen. The crate should pop out.

Method 2: allow the game through the firewall

This is the official method from the developers' support site. Check that the Killing Floor 2 game executable is not affected or blocked by your firewall. You can find it in the game's Binaries\Win64 folder, for example C:\Program Files (x86)\Steam\steamapps\common\killingfloor2\Binaries\Win64.

Method 3: use a VPN (worked for the author)

While searching for solutions the author read that some countries, Russia and Indonesia among them, block connections to the reward system. From his investigation this affects only weekly or seasonal rewards and vault crates, not random drops. He installed a free VPN app from the Microsoft Store, connected, launched KF2 and went to the vault. After waiting for the meter to fill and the crate to arrive, he pressed Shift+Tab twice, opened the inventory and found the crates and the weekly rewards he had missed.

If the first two methods fail, try this one.

If nothing works

The author's conclusion is that the reward servers were unreliable at the time. If none of the methods helps, report it to Tripwire support and hope for a fix in a later patch.

FAQ

How do I get a vault crate that did not show up?: Right after the vault meter fills and the game awards a crate, open the Steam overlay with Shift+Tab quickly and go to the in-game inventory. The crate should then pop out.
Which file should I allow through the firewall?: The Killing Floor 2 executable in the Binaries\Win64 folder of the game, for example C:\Program Files (x86)\Steam\steamapps\common\killingfloor2\Binaries\Win64.
Why would a VPN help?: The author found a report that some countries, such as Russia and Indonesia, block connections to the reward system. He says this stops weekly or seasonal rewards and vault crates, but not random drops.