I have just checked out your site. 

Please notice the red lines:

they should be something like /ow_static/plugins/spvideolite/js/vendor/base64.min.js without the version numbers.

Please tell me where you download the install package. It's probably that you downloaded a Source Code package, it doesn't contains enough resources to run. Please use compiled packages to install.

The "Download ZIP" button will NOT work.

make sure you download the right package spvideolite_v210.zip 

from https://github.com/SongPhi/spvideolite/releases

Please uninstall and delete the old version. Then install the correct package, you should be ok.

Regards,

Thao

vielen Dank SongPhi