Source 2007 mods: Unable to join/create servers, or view achievements (218)

Compatibility Report

• Name of the game with compatibility issues: Source SDK Base 2007 / Source Mods
• Steam AppID of the game: 218

System Information

• GPU: Radeon RX 560
• Driver/LLVM version: Mesa 18.0.5/6.0.0
• Kernel version: 4.15.0-43-generic
• Link to full system information report as Gist: https://gist.github.com/scqless/11cf687d4980f2578ad691f56e9dda5c
• Proton version: 3.7, 3.7 Beta, 3.16, 3.16 Beta

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

steam-9856914317583057114.log

Symptoms

Hello,

Thank you for recently adding the option to force apps to use Proton. This makes it possible to launch Source 2007 mods on Steam for Linux. However, multiplayer mods are unable to create/join servers, or view achievements. The following were observed when playing a multiplayer mod:

Server Browser: Steam Beta must be running to make use of Find Servers

Connect by IP: The server requires that you be running Steam.

Create listen server: CD Key authentication invalid for internet servers.

View achievements: You must be logged in to Steam to unlock or view achievements

Reproduction

1. Opt into the Steam Beta
2. Force Source SDK Base 2007 to use Proton
3. Install Source SDK Base 2007
4. Install a multiplayer Source mod. I used GoldenEye: Source
5. Attempt any of the above tasks under Symptoms

Start with the attached Proton log and the listed reproduction steps using Source SDK Base 2007 and GoldenEye: Source. Compare the server browser, IP connection, listen-server, and achievements failures across the reported Proton versions. Done means multiplayer server actions and achievement viewing work under Proton.