Write BluRay from hard disk

[DonkeyKong]

Why are you trying to open your folders with DVDFab? Do you want to compress your content or what. If you want just burn - open it with ImgBurn and burn it.
By the way, just selecting ImgBurn in DVDFab as burning engine isn't good enough. Please read instructions and/or video and set it up as recommended there.

No, the content of the folders are already compressed.

what file system ist compatible with bluray player?

ISO 9660 + UDF + JOLIET ??