Modern security programs like Windows Defender sometimes flag steamclient64.dll as a false positive and quarantine it.
folder like a surgeon looking for a rogue clot. He reinstalled the Steam client, watching the "Estimated Time Remaining" flicker like a dying candle. Nothing worked. The error message sat there, smug and static, mocking his $3,000 rig. unable to load library steamclient64dll fixed
Try running the game in compatibility mode: smug and static