If this guide helped you, share it. If you are still stuck, the Sonic Adventure 2: Chao World Discord server and the SADX Modding Forum have pinned threads specifically for steam_api.dll issues.
: If the file is found, restore it and add the Sonic Adventure 2 installation folder to your exclusions list to prevent it from being deleted again. Manual Reinstallation (Last Resort) steam apidll sonic adventure 2 upd link
If you are encountering a missing steam_api.dll Sonic Adventure 2 If this guide helped you, share it
After verifying, stop your antivirus from eating the file again. If this guide helped you
Sometimes the error isn't the DLL itself, but the underlying software needed to run it.