@phreak, I did try to upload it to Applications! But when I put it in the Plugins folder, I get the same problem as @cryptoguy: the "Something has gone wrong" screen.
Thank you for trying to help! I'm afraid that gives me the "Something has gone wrong" screen as soon as I click on the message to update the cache - before even activating the plugin.
I have the same problem. Installed the latest plugin from vanilla forum and I get the "Something has gone wrong."screen. On the latest version of vanilla forums. Shame because I really wanted to use YAGA.