Issues downloading H5P content from one server to another

Hello All. I have tried to migrate h5p content from an old server to a new one, however I keep getting the error:

Validating h5p package failed.

The file you uploaded is not a valid HTML5 Package (We are unable to unzip it)

I tried doing this a few ways: first, by reusing it from a single h5p activity within the browser; download was fine and downloaded with a .h5p extension; tried to upload and got the error shown above.

Secondly, I tried to do this via Filezilla and received the error: 

 open for write: permission denied

Error: File transfer failed

I don't think my files are corrupt as I can see them in the old site and they work fine in browser in the dashboard of my wordpress site.

I have tried doing this with various types of h5p content and it doesn't seem to matter which one; they all do not transfer over. 

Any assistance would be appreciated as I have 24 pages of h5p and it would be a tad disheartening to lose them :...)

Thank you!