Warhammer 40,000: Space Marine 2 Known Issues and Workarounds: Crash, EAC, and Server Fixes

Easy Anti-Cheat service failing to authenticate against Epic Online Services (EOS) background redistributables, or colliding with Windows kernel-mode security checks. To fix this: Open your Steam Library, right-click <em>Space Marine 2</em> &rarr; <strong>Manage</strong> &rarr; <strong>Browse local files</strong>. Navigate to the <code>EasyAntiCheat</code> folder, right-click <code>EasyAntiCheat_EOS_Setup.exe</code>, and select <strong>Run as administrator</strong>. Choose <em>Space Marine 2</em> from the product list and click <strong>Repair Service</strong>. Press <kbd>Win + R</kbd>, type <code>%APPDATA%\EasyAntiCheat</code>, press Enter, and delete the cached certificate files inside. Ensure both <code>Warhammer 40000 Space Marine 2 - Retail.exe</code> and <code>start_protected_game.exe</code> are allowed through Windows Defender Firewall.

UDP socket negotiation timeouts and crossplay matchmaking handshake stalls between regional relay servers when loading the Battle Barge or starting PvE Operations. To fix this: From the main title screen, open <strong>Settings</strong> &rarr; <strong>Game</strong> &rarr; toggle <strong>Crossplay</strong> to <strong>Disabled</strong>. Same-platform matchmaking bypasses external relay routing and connects instantly. Change your Windows or router DNS to Google DNS (Primary: <code>8.8.8.8</code>, Secondary: <code>8.8.4.4</code>) or Cloudflare DNS (<code>1.1.1.1</code>) to resolve domain resolution delays with Epic Online Services. Forward UDP ports <code>27015–27030</code> and TCP ports <code>27014–27050</code> in your router's port forwarding table to prevent NAT drops during squad assembly.

Recent game updates triggered a compatibility fault with Proton Experimental and standard Proton 9 runtime bridges during EAC anti-cheat launch verification. To fix this: In your Steam Library, select <em>Space Marine 2</em> &rarr; click the gear icon &rarr; <strong>Properties</strong>. Select the <strong>Compatibility</strong> tab, check <em>'Force the use of a specific Steam Play compatibility tool'</em>. Select <strong>GE-Proton9-15</strong> (available via ProtonUp-Qt) or fall back to <strong>Proton 8.0-5</strong>. Under General &rarr; <strong>Launch Options</strong>, paste: <code>PROTON_NO_ESYNC=1 %command%</code> to stabilize frame pacing on Linux kernels.

Raptor Lake voltage and transient boost spikes cause decompression errors in the Oodle Kraken library during early shader pre-compilation, incorrectly triggering an out-of-VRAM error dialog. To fix this: Ensure your motherboard BIOS has the microcode 0x12B update installed. In BIOS, select the official <strong>Intel Baseline Profile / Default Settings</strong> to enforce factory power limits (PL1=125W, PL2=253W, ICCMax=307A). If shader crashes persist on desktop launch, open Intel Extreme Tuning Utility (XTU) and reduce the Performance Core Ratio by 1x (e.g., from 55x to 54x) prior to compiling shaders.

Exiting an online match prior to returning to the Battle Barge aborts the secure handshake with Saber's profile database, triggering a local state fallback that does not credit recent armory data. To fix this: Never force-quit (Alt + F4) or dashboard during the victory or defeat summary screen; wait until your character physically stands on the Battle Barge deck before exiting the session. Be aware that progression earned while launched in true Offline Mode remains separate from Online Operations by design to prevent client-side data tampering. If a weapon perk point fails to appear after completing a mission, switch classes in the Armory once to force the game client to refresh its active inventory cache.

DLSS 3 / FSR Frame Generation desynchronization with in-game V-Sync buffers during massive Tyranid swarm rendering waves. To fix this: In the in-game Video menu, set <strong>V-Sync to OFF</strong>, and force V-Sync globally through the NVIDIA Control Panel or AMD Adrenalin software. Lower <strong>Volumetric Fog Quality</strong> from Ultra to High; this single setting restores up to 18% in 1% low frame rates during swarm horde battles. Set <strong>Motion Blur</strong> to 0% to prevent camera pan judder during intense melee parry exchanges. Use an external frame limiter (such as RTSS) to cap FPS to your monitor's native refresh rate.

Early launch builds constrained all non-16:9 viewports with vertical black bars across gameplay and UI layers. To fix this: Verify that your game client has received Title Update 3.0 or newer via Steam. In Video Settings, select <strong>Borderless Windowed</strong> at your native ultrawide resolution (e.g., 3440x1440 or 5120x1440). Adjust the in-game <strong>Horizontal FOV Slider</strong> to 85–95 degrees to compensate for edge distortion on wider aspect ratios.

Steam Input's virtual translation layer conflicting with the Swarm Engine's native DirectInput gamepad hooks, causing missed melee parry inputs. To fix this: Open your Steam Library, right-click <em>Space Marine 2</em> &rarr; <strong>Properties</strong> &rarr; <strong>Controller</strong>. Set the override dropdown to <strong>Disable Steam Input</strong>. Connect your PlayStation DualSense or Xbox controller via a wired USB-C cable to enable full native haptics, adaptive triggers, and zero-latency parry timing.