If you are seeing the "Age of Empires 2 Definitive Edition tampering detected" error, don’t panic. This article explains exactly what this error means, why it happens (even if you aren't cheating), and the 10 proven methods to fix it for good.
Wait for the process to finish (this can take a few minutes), then restart Steam and try launching the game. Open the Xbox App on your PC. Select AoE2: DE from your installed list. Click the three dots (More Options) and select Manage . Go to the Files tab and click Verify and Repair . Step 2: Disable or Unsubscribe from Mods age of empires 2 definitive edition tampering detected