I haven't been able to play FHS for days using gameroom. Its driven me nuts. First it said that flash wouldn't work as I didn't have it installed when I knew I did. It seems that was a known issue from one of @Xarly's posts I saw earlier.
A lot of googling and it seems many have the same issue and then I came across a random post on a microsoft forum. It seems the newest windows update has caused incompatibility issues with gameroom. I uninstalled gameroom and then could not reinstall as it said it couldn't validate the files. This is how I got it working.
Find the download in the download folder for gameroom. Right click on it. Choose troubleshoot compatibility and follow the prompts. I chose it wasn't working with this version of windows, the options it gave me didn't list windows 10 so I used 8. It ran the fix, I clicked test it now, it installed the file, gameroom opened.
I suspect windows might at some point update with the fix but at least it works now. If you are having the same issue, try it 