Re-download or ask for a new copy of the file.
Once extracted, you will likely find a folder containing several files. BD-Y-SB-2-3x.7z
This indicates a 7-Zip compressed archive , which allows for high compression ratios, similar to a .zip file but often smaller. Name Breakdown (Inferred): Re-download or ask for a new copy of the file
If prompted, the creator of the file must provide the password. If you can tell me: Where did you download this file from? which allows for high compression ratios