All of the .mif files in that directory have a size of 0; so there’s no chance of reading anything from them. This can happen if the target filesystem runs out of storage space at write time, but isn’t the only possible reason.
The most useful thing for us would be if you can consistently reproduce the problem within a specific set of circumstances; there’s not enough information for us to work with if it’s just a single observation of an error. So, for instance:
- Does the issue occur exclusively when writing to the external NTFS file system? Let us know what other targets (file system & internal/external) you are or are not able to successfully write to.
- Is it influenced by whether or not the external drive is ‘safely’ removed after writing to it?
- Is it definitely confined to the .mif file format? I.e. Can you write multiple .mif files to the drive and they are all empty, then write multiple .nii files to the drive using the same command and they are all OK? If so, what about other image formats?