Fix: Undertale won’t launch

By: Ivan Jenic
3 minute read

Undertale is one of the best if not the best indie game Steam has to offer. From the moment the game was introduced, it received the worldwide recognition that led to multiple awards and millions of sold digital copies.

If there is a super-undemanding-stable game category, Undertale must be at the leading spot. However, there are issue or two that may prevent you from enjoying this amazing game. It seems that the game won’t launch for no apparent reason. But, don’t worry, we prepared a few workarounds to help you overcome this issue.

What to do if Undertale won’t launch

1. Use Steam tool to repair local files

Steam offers a neat tool that will help you repair game installation local files. Namely, in some occasions due to corruption or misuse of game files, the game won’t start. So, instead of uninstalling right away, try out repairing local files. You can do that by following these instructions:

  1. Open the Steam Client.
  2. In Library, right-click Undertale and open Properties.
  3. Open Local files tab.
  4. Choose Verify integrity of game files.
  5. Restart Steam and try running the game.

2. Start the game from its folder instead from Steam

As we all know, with the implementation of the Steam desktop app, all the games run trough the client. However, on some occasions, the Steam app can provoke a lot of problems. We advise you to try and run Undertale from installation folder instead of the client.

You can do that this way:

  1. Close the Steam client and exit from the notification area.
  2. Open Task manager and stop the Steam process.
  3. Find your way to the Undertale installation folder.
  4. Double-click Undertale.exe and run the game.

Have in mind that Steam client may start, nonetheless. If that is the case and the game is still faulty, move on to a next solution.

3. Delete Steam_api.dll file

It’s quite hard to play Steam games independently, without Steam DRM. However, there are some games that are DRM-free, and luckily, that is the case with Undertale, too. So, you can delete Steam_api.dll and try running the game without Steam. And this is how:

  1. Close your Steam and kill related processes in Task manager.
  2. Go to the Undertale installation folder.
  3. Find steam_api.dll and back it up.
  4. Delete file from the folder.
  5. Start the game from Undertale.exe
  6. Additionally, you may try and run it trough Steam if Undertale.exe won’t start the game.

This may prove harder to do for many games, but the Undertale should function well. If the things take a wrong turn, you can always restore a file from the backup location.

4. Extract Undertale.exe file

Some witty users from Steam community forum presented an interesting solution for this issue. Namely, it seems that the game’s ”exe” file can be extracted with WinRar or similar software. This way you’ll get new ”exe”file that, as they stated, works like a charm. We will present you whole procedure step-by-step.

  1. Close the Steam app and kill all its processes in Task manager.
  2. Find your way to the Undertale installation folder.
  3. Right-click Undertale.exe and choose Extract here with WinRar.
  4. When asked to replace or rename Undertale.exe, choose rename and change its name to UndertaleOld.exe
  5. The new Undertale.exe that is extracted is your new game launcher.
  6. Try launching the game.

In the case of any problems, you can delete newly appointed launcher and rename UndertaleOld.exe to just Undertale.exe.

5. Reinstall the game

We came to the last resort. If you haven’t solved your Undertale issues with the previous workarounds, reinstallation is the only viable option. We will lead you trough the process.

  1. Go to the Steam client.
  2. Open Library and right-click Undertale.
  3. Choose Uninstall.
  4. Use some kind of registry cleaner to get rid of registry remainings.
  5. Open Steam client and Library.
  6. Find Undertale and select Install.

After the process is finished, you should be able to play the game seamlessly.

We hope you were able to start the game by using these workarounds. In addition, if you have any questions or suggestions, please be free to tell us in the comments bellow.


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