Did the error happen , or did the game work fine before suddenly stopping?
— Search for a reliable source to download CryEA.dll . Exercise caution when downloading DLL files from the internet; always scan downloaded files with your antivirus before use.
If you have the archive, look inside the crack or game folder for cryea.dll and manually copy it into the game's or root folder.
If you already completed the installation but face this error, the missing file is likely sitting inside your operating system's security vault.
Add your entire Crysis 3 installation folder to the exclusion list. This tells your computer to never scan this folder for threats. Disable your antivirus temporarily (for 10 minutes).