Hi Asphault365,
It appears there is a setting on your server that is blocking the download and installation of the plugin. If you have access, try adding https://www.methodintegration.com to your Trusted Sites in your Internet Options.
If this doesn’t help, you can try playing around with the additional settings under the Security tab, but I recommend that you speak with your IT admin for further details.
I hope this helps.
Audisho