Hello, Hector!
Thank you for noticing the problem. We will check that and if we find that problem is on our side it will be fixed very soon.
In the meantime, if you are unable to install the plugins through WordPress, please download them from the following links:
Vision core
After that, Install the plugin manually through the Dashboard->Plugins->Add new…Upload Plugin
https://prnt.sc/pp05u3
Here are the other two :
Layer Slider
Slider Revolution
Regards