Serving Local Nifti files Question

Hi - My goal is to view a local nifti file (.nii) on the neuroglancer demo appspot. So, I made a directory and placed the file in it, then ran [cors_webserver.py](https://github.com/google/neuroglancer/blob/master/cors_webserver.py) to serve that directory. However, when I entered the corresponding url into neuroglancer: `nifti://` I got a `Failed to parse NIFTI header.` error. I thought this might be the .nii file format so I tried again with separate hdr and img files but stll got an error.

My .nii file is from the [nitrc](https://www.nitrc.org/projects/nifti) website, so I don't think it is a case of a corrupted file. I wanted to ask if there is something obvious that I am doing wrong? Do I need to change the name of the nifti file or something?

Thanks in advance.