Hi elena,

Sorry for the terribly delayed reply; I didn't realize we had a Forums!

There's issues with reading CIFTI files stored on the cloud, sometimes. So if the package has been downloaded onto the cloud, reading files included in the package may fail. 

We're looking into a workaround that involves saving a copy of the desired to the disk as a temporary file, reading that in, then deleting the temporary file. Meanwhile, you may have to download the package to the disk, or implement this workaround yourself as necessary.