It's important to recognize that some password-protected archives cannot be opened without the correct password. WinRAR's official documentation states there's no backdoor for lost passwords. In such cases, the only options are finding the password through legitimate means or abandoning the file altogether.
If the password still fails, the file may have experienced data degradation during download. This is a common issue with large PC game files. To fix this, delete the temporary cache files in your browser and re-download the archive using a dedicated download manager like Internet Download Manager (IDM). Why Web Platforms Use Archive Passwords Kookdownload.com Password