Error reading nii and nii.gz images

[HoileongLee]

I got the following errors while I am trying to read a nii image:

irtkFileToImage::New: Unknown file format /Users/Daniel/Desktop/ProtonImages/0001H1.nii libc++abi.dylib: terminating with uncaught exception of type irtkException Abort trap: 6

How could I resolve this error?

Thank you.