My Passport Ultra doesn't save certain movie files made on Mac iMovie?

I bought a My Passport Ultra to save my  movie files, which I do on a regular / annual basis when one storage is getting full, I like to have duplicates of all the movies and photo libraries since it’s a lot of work that one doesn’t want to lose by accident. My main external storage is a WD My Passort Pro which I bought last year and it works great.

When I got this new WD Ultra, I reformated it for my Mac OS and I saved my iPhoto Library first  from my other main storage, the WD Passport Pro through my computer where both were connected. The file was a large 230 GB file. It all went well. Then I tried to back and save my movie files, also a large one, 160 GB, but this time it told me : 

" The item “iMovie 2015” can’t be copied because it is too large for the volume’s format"

Whereas it had obviously plenty of space. So what I noticed is then I tried to copy individual movie file, but the same message appeared. However, when I copied other files from my WD Pro, it did let the files to be copied, only these Movie files were not allowed to be copied.

They are all QuickTime Movie files and again, I have other WD storage that used before and this never happened with these movie files, any ideas anyone what causes this restriction on these files?

Hi there,

What file system is the drive partitioned with? If you have FAT 32 you will have a 4 GB limitation, if one file that you copy to this drive had more than 4 GB it will not copy, however if the files you have on the drive are less than 4 GB it will not affect the limitation even If you have 100 GB worth of files that have less than 4 GB.