When the system throws the "Tampering Detected" error, it is essentially saying: "The file hash on your hard drive does not match the official hash on the server. Something has changed this file, and I assume it is malicious."
A: Add PROTON_NO_FSYNC=1 %command% to your Steam launch options. The anti-cheat struggles with futex syscalls on Proton. Conclusion The "Tampering Detected" error in Age of Empires II: Definitive Edition is a terrifying popup, but it is rarely your fault. It is the digital equivalent of a nervous guard dog barking at the mailman. age of empires 2 definitive edition tampering detected fixed
A red error box slams your screen: