Thank you for getting in touch with us. My name is Attila and I'm happy to assist you today. I appreciate your patience while we've been working towards your ticket.
We do not own any theme, so I'm not sure that this message is related to us as it mentions themes.
When uploading informs this message:
Unpacking the package...
Installing the theme...
The package could not be installed. The theme does not have a style. css stylesheet.
Theme installation failed.
Hello pbelotto,
Thank you for getting in touch with us. My name is Attila and I'm happy to assist you today. I appreciate your patience while we've been working towards your ticket.
We do not own any theme, so I'm not sure that this message is related to us as it mentions themes.
But as for LayerSlider's installation, you can find step-by-step guide in the documentation: https://layerslider.kreaturamedia.com/documentation/#installation
One thing to look out for is to use the installable zip inside the package.