Signing Into Xbox App First Fixed Sign-In Crashes

The Problem

Launcher crashed every time during Microsoft sign-in. White screen, then close. Event Viewer showed errors related to Xbox identity services.

The Fix

1. Updated Xbox app from Microsoft Store
2. Opened Xbox app and signed in successfully
3. Left Xbox app running in background
4. Opened Minecraft Launcher: sign-in completed without crash

After that first successful login, I could open the launcher without the Xbox app running. The initial sync seemed to need Xbox infrastructure active.

Guide: launcher crashes on sign-in.