Hello, I managed to unpack the firmware but it gives me the following error:
[root@localhost Dahua-Firmware-Mod-Kit]# ./extract.py dvr.bin -c NVR4xxx
WARNING Found config: NVR4xxx
INFO    Extracting 7 files to: 'dvr.bin.extracted'
INFO    Processing 'Install.lua'.
INFO    Processing 'u-boot.bin.img'.
INFO    Processing 'romfs-x.cramfs.img'.
INFO    Processing 'web-x.cramfs.img'.
INFO    Processing 'custom-x.cramfs.img'.
CRITICAL        Missing dependency: 'cramfsck'
ERROR   'CramFS' handler returned non-zero return value for file: 'custom-x.cramfs.img.raw'
Traceback (most recent call last):
  File "./extract.py", line 238, in <module>
    extractor.Extract(args.source)
  File "./extract.py", line 113, in Extract
    raise Exception("Handler returned non-zero return value!")
Exception: Handler returned non-zero return value!
how can I solve it?