Windows Side-by-Side Configuration Error — SxS Assembly Failure

Windows side-by-side configuration error means an application cannot start because its required assembly (DLL version) is missing or the manifest is corrupted. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Full message: 'The application has failed to start because its side-by-side configuration is incorrect'. SxS (Side-by-Side) manages multiple versions of the same DLL on the system. The application manifest specifies exact DLL versions it requires. Usually means a required Visual C++ Redistributable version is missing. Event Viewer > Application log shows the exact assembly name and version that failed. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Required Visual C++ Redistributable version not installed. Corrupted C++ Redistributable installation. Application manifest referencing a specific assembly version that does not exist. WinSxS folder corruption preventing assembly binding. Partial application installation missing some dependent assemblies. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Check Event Viewer > Application log for SideBySide source events — note the assembly name and version. Install or repair Visual C++ Redistributables: download all versions (2005-2022) from Microsoft. Reinstall the failing application completely (uninstall first, restart, reinstall). Run sfc /scannow to repair corrupted system assemblies. Run DISM /Online /Cleanup-Image /RestoreHealth to repair the component store. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Windows Error Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.