Plugins failed to install

The icon preview has nothing to do with whether or not the plug-in will load in After Effects. That's just Windows not displaying an icon for the given extension, it happened to me yesterday. Twitch is an extremely old plug-in and hasn't been updated in years, so it's likely not going to support the latest versions of After Effects. You can contact VCP support, but they will likely tell you it's no longer a supported plug-in.

From the look of your image you didn't actually unpack the zip folder, hence the normal system file associations aren't used. Other than that you simply could have messed up said file associations or the files are damaged.

Mylenium

I take it you've followed the installation instructions and that screenshot isn't inside a zip file?

Have you emailed Video Copilot's support, they have always been very responsive with me.

Is it Video Copilot Twitch? Do you mean you do not find twitch file after you copy it into the plug-in folder? Is it Mac or Win?