This guide will explain why this error happens and, more importantly, how to fix it safely so you can get back to saving the world with Sonic and Shadow.
A failed update or improper shutdown can leave the DLL file unreadable. Steam Api.dll Sonic Adventure 2 -UPD-
: Acting as a primary layer of Digital Rights Management; without it, the game cannot communicate with Valve's servers to authorize a session. Common Issues and Causes This guide will explain why this error happens