How to fix KB5013943 causing application error on Windows 11?

Hello, I did Windows update installation quite recently and since then I have been facing an issue with opening various applications. KB5013943 causing application error appears on the screen all the time when I open any apps. I can’t understand what’s wrong is actually happening with the device. ¡Por favor! Ayúdame.

Recently, Windows 11 users have reported an issue where they can’t open their apps. The issue seems like to occur after they install the latest KB5013943 cumulative update. The update is supposed to fix the security vulnerabilities and various bugs.

Called specifically, the update is to fix bug causing .NET Framework 3.5 apps not to open when they use Windows Communication Foundation (WFC) and Windows Workflow (WWF) components. However, now the people reported about the problem with the following apps:

  • ProtonVPN,
  • Potencia Shell,
  • Visor de eventos,
  • Sound Blaster Command,
  • KeePass,
  • Estudio visual,
  • Discord,
  • and ShareX.

The full error message reads as:

The application was unable to start correctly (0xc0000135). Click OK to close the application

The KB5013943 update is making the situation worst for the users. The people are looking for fix on security forums. In this article, we have provided three best fixes that you should try to get rid of the issue. If these fixe do not work, wait for the official fixes released from Microsoft official.

You can also use PC Repair Tool – an automatic tool to check for PC related issues and repair them automatically. It is effective tool to fix most system errors, BSODs, corrupted files and registry issues. Here is its direct download link.

Manual fixes for KB5013943 causing application error

Fix 1: Enable .NET 3.5 Framework in the Control Panel

  • Open Control Panel,
  • Go to Programs,
  • Pick Turn the Windows Feature on or off,
  • Make sure that you check .NET Framework 3.5 (includes .NET 2.0 and 3.0) and Net Framework 4.8 Advanced Services boxes,
  • Enable the .NET 3.5 Framework from the Control Panel now and see the changes.

Fix 2: Enable .NET 3.5 Framework using Command Prompt

  • Open Command Prompt as Admin,
  • For this, type cmd on the Windows Search, right-click on Command Prompt and select Run as Administrator,
  • Type the below commands in the command line and hit Enter on each time:

dism /online /enable-feature /featurename:netfx3 /all

dism /online /enable-feature /featurename:WCF-HTTP-Activation

dism /online /enable-feature /featurename:WCF-NonHTTP-Activation

  • Close the command prompt and check now if KB5013943 causing application error continues.

Fix 3: Uninstall KB5013943 update

  • In the settings, select Windows Update,
  • Under it, click on Update History,
  • Go to the Related Settings section and choose Uninstall Updates,
  • Select the problematic update from the list and click on Uninstall,
  • Click Yes now on the prompt to continue.

¡Eso es todo! We have provided all possible fixes for KB5013943 causing application error. Hope so, these methods work in your case. The best option is to use the recommended product. Uninstalling the recent update would leave your device unprotected from the latest security threats, keep this always in mind.