Please refer to the the Steam Troubleshooting and How-To's knowledge base. It contains a lot of helpful advice for many common problems. It is also available in several different languages.

In particular, the following article is a good starting point for download and install issues:
Solving Download and Game Install Issues

Occasionally the game files can become corrupted and you won't be able to launch the game. This usually seems to happen after Steam updates the game. If this happens, verifying the game files should fix it:
Verify Integrity of Game Files

Anti-virus software can also cause issues sometimes. In particular, AVG is known to cause problems. To test if your anti-virus software is the cause, try temporarily disabling it and see if problems persist. If disabling it fixes the issue, then you should be able to add an exclusion for Final Days as a permanent solution.

Make sure that the game is configured correctly for your keyboard type. There are presets available for both "WASD" (QWERTY keyboard) and "ZQSD" (AZERTY keyboard).
The options for this are under: Options > Control Options > Key Bindings

Final Days works natively with Xbox 360, Xbox One, and Steam controllers. It should also work with most modern “XInput” twin-stick controllers. However, it does not natively support older “DirectInput” controllers.

This can happen when you've enabled "Xbox Configuration Support" in Steam (under Big Picture > Settings > Controller Settings). In this case, Steam will override Final Days native support of Xbox controllers and use its own configuration. To get around this, either disable "Xbox Configuration Support", or change the "Steam Input Per-Game Setting" for Final Days to "Forced Off" (Big Picture > Library > Final Days > Manage Game > Controller Options).

Some controllers (e.g. Logitech F310) allow you to switch between XInput and DirectInput. If this applies to your controller, make sure that it’s set to XInput.

Playstation 4 controllers should also work by default in Steam. I've published an official Steam controller configuration which emulates it as an Xbox controller. The only problem is that it appears in Final Days as an Xbox controller, but apart from that it works well.

Please refer to this guide:
http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=780950557

Final Days currently requires Windows Media Player (WMP) for music playback (it's to do with the framework it's using). Eventually I want to remove this requirement, but unfortunately for now I'm stuck with it.

If you can't (or don't want to) install WMP, then you can still play Final Days with music disabled. When prompted to install WMP, just say "no". It will then ask if you want to play anyway with music disabled. Alternatively, you can disable music (and the WMP requirement) with the command line switch: /nomusic

This is likely due to a quirk of the framework I'm using. For sounds to work, you must have speakers (or headphones) plugged in BEFORE you launch the game.

If the game happens to crash (which should hopefully be a rare occurrence), then you should get the option to send the crash report to me. These crash reports help me a lot with diagnosing and resolving the problem, so I strongly encourage you to send it.

Please include as many details as possible (e.g. what you were doing, steps to reproduce, etc), as well as a screenshot if it’s helpful. If you’d like me to get back to you about it, please be sure to also include your e-mail address. Or alternatively, contact me about it after you've sent the report.

Once I receive your crash report, I will endeavour to find the cause of the crash and resolve it as quickly as possible.

Please send me as many details as you can provide such as:

• Description of the problem you're having
  
• Where/when in the game did the problem happen
  
• Steps to reproduce
  
• PC specs
  
• Final Days log files

I will endeavour to resolve the issue for you as quickly as possible.

The log files are located here:
To easily send me the log files, follow these steps:

1. In your Steam library, right-click on "Final Days" and select "Properties".
   
2. In the properties window, go to the "Local Files" tab and select "Browse Local Files".
   
3. When the "Final Days" folder opens, you should see an application named "LogUploader". Double-click this.
   
4. The "Final Days Log Uploader" application should then appear.
   
5. You can optionally enter your e-mail address and any notes you might want to mention (e.g. description of the problem, steps to reproduce, etc).
   
6. Click the "Upload Log Files" button to upload your log files to me.

Here's a few ways you can report issues to me:

• Making a post on the forums: http://gtm.steamproxy.vip/app/459830/discussions/
  
• E-mail: support[at]plus7software[dot]com
  
• Discord: https://discord.gg/finaldays

Cheers,
Mike
+7 Software