If the connection file itself is damaged, resetting it forces Steam to rebuild the digital rights management bridge.
If you are still stuck after these seven steps, check your antivirus logs. Avast, AVG, and McAfee are known to quarantine steam_api.dll because it "looks like a hack tool" (false positive). Restore the file from quarantine, add the Resident Evil 6 folder to your AV exceptions, and you will finally be able to enjoy the wonderfully ridiculous over-the-top action of RE6. fatal error failed to initialize steam resident evil 6 upd