I tried to look into this, and based on the error message, it seems like there might be an issue with the browser permissions to run the game. Could you please try clearing your browser cache and reloading the page? If that doesn't work, try using a different browser or disabling any ad-blockers or extensions that might be interfering. Let me know if it works.
Regarding your question about a Linux version, the version of RPGMaker I use doesn't show a deployment option for Linux, so I'm not sure if that's possible at the moment. Sorry about that!