There are many posts for help in starting Space Marine. Hopefully I have collected the solutions here and that these will be of some help.

I am happy to update this guide if you find other actions that work.

98% of the issues starting Space Marine can be resolved by verifying the local game files:

From Steam Support:

1. Restart your computer and launch Steam
2. From the Library section, right-click on the game and select Properties from the menu.
3. Select the Local files tab and click the Verify integrity of game files... button.
4. Steam will verify the game's files - this process may take several minutes.

https://support.steampowered.com/kb_article.php?ref=2037-QEUH-3335

If verifying the game files didn't work - what next ?

1. Check that a recent update to your anti-virus software hasn't decided to block Space Marine. (this is not common but not unknown). Try disabling AV and relaunching, if this works add Space Marine program / directory to the AV exceptions, restart your AV and try again.

2. You may have a software firewall installed (or the windows default firewall) - again a recent update may have decided to block outbound connections for Space Marine. If you can temporarily disable it - do so and try again, and if successful, add to the allowed programs list.

It is entirely possible that these won't work for you, from personal experience this has been a solution.

It could be that your local network has blocked the activity as Space Marine uses Peer-to-Peer connections and is not server based. (talk to your Network Admin ;) )

This can be caused by too high a resolution being set in game.

A work around is to launch the game in "window" mode and once running choose a different resolution in the game settings. Once changed remove the "window" start option and try again.

• Open Steam
  
• Go to the "Library"
  
• Right-click the game which needs to be reconfigured
  
• Select "Properties" from the menu
  
• Click the "Set launch options..." button
  
• enter -window
  
• Close menu and launch game

Space Marine works natively on Windows 10 or Windows 11. Although some people have had to set it run as "Administrator" (possibly as they don't have Administrator accounts), and others have set it to Windows 7 or 8 compatibility (it was released for Windows 7). You may need to combine Administrator and compatibility.

Multi-core systems Systems running with more than 8 cores may for some reason be unable to launch (reported resolution was to disable cores to reduce down to 8 for Space Marine).

"Hydran Agent

Found out finally what it was folks. Its because of the amount of cores on the PC was more than 12.

So go to here:

https://github.com/adrian-lebioda/SpaceMarineCoreFix

1: Download and install x86 Visual Studio 2022 Redistributable
2: Copy DINPUT8.dll to the install directory of Space Marine (next to SpaceMarine.exe)
3: Launch game

It works flawlessly now. Dont know why this wasn't officially patched."

You could also try setting CPU affinity for the game process - https://www.supportyourtech.com/tech/how-to-set-affinity-windows-11-a-step-by-step-guide-for-beginners/


C++ may be having some impact - anytime the game re-installs or an older game is installed it re-adds older C++ versions, see post below:
https://steamproxy.net/groups/78832/discussions/23/617328415057830843/

Running 'Flawless Widescreen' has been reported as affecting start-up / loading saves [thanks https://steamproxy.net/id/Ludwig_von_Liberty]