If the password doesn't work, ensure there are no extra spaces before or after the text. If you are seeing a "checksum error," the file may have been corrupted during download and might need to be re-downloaded.
In rare cases where scene groups or uploaders password-protect archives to prevent automated copyright takedowns, the password is almost always the URL of the site you got it from. You can try entering ryuugames.com (lowercase, no quotes). 🛡️ How to Protect Your System ryuugamescom password better