OK, I will say that I have the updated Plug-in and am using Mozilla Firefox, so that you know I have the right programs and stuff.

When I bring up the game window, by pressing Play Game on the game page of some GBA games in the RGR. I've tried a few Pokémon games, DBZ Legacy of Goku II and a couple other games. Anyway, the emulator starts to load, but about halfway through the loading bar, it stops and a download of the ROM starts, instead of the game actually starting up. The download is a .gba file, so I know it is the fault of the Vizzed site, as I only have one other tab opened, and it is Facebook.

Is this common? It has been happening only for a couple hours now. In the past, the game actually came up.

This is the first time I ever heard of this...
Are you using any kinda download accelerator?
Are you also using the latest version of the plugin? (2.40)
It doesn't make sense that its downloading .gba files, because the plugin downloads them as zip files then extracts them.

Try Super Mario Bros for NES linked here:
https://www.vizzed.com/play/super-mario-bros-nes-online-nintendo-nes-478-game

Please try both emulators and see if either of them work.
(FCEUX and MEDNAFEN)

Vanelan : It has only been doing this for GBA games, not NES, N64, SNES, etc. games. It hasn't done it at all yesterday, but it has started doing this again today.

I've never heard of the game play/loading stopping while downloading a file before.

Just to be clear. The site does download a Rom file to your computer's hard drive the first time you play them, but that process shouldn't stop the play window.

As Vanelan said, the file downloaded is a zip file that gets converted, so I'm not sure what the problem could be here. My theory is that it's an issue with your anti-virus or some strange web browser plugin.

Have you tried playing a game with a different browser to see if the same issue occurs?

Does this only happen the first time you try to play a GBA game, or all the time?

Does it happen with BOTH the Visual Boy advanced emulator as well as the Mednafen?

I'm also kinda confused because when I look at your game play history, it says you have only tried to play Sonic and Knuckles, Monopoly and Pokemon emerald, yet you say you have tried other games. So I'm not sure what the issue here could be aside from what I mentioned before.

I'm also not able to re-create the issue with GBA games using either Chrome or Firefox. Which version of windows are you running?

That is very strange since, like I said in the previous post, they are downloaded as zips...

Do you have chrome installed? There is a possibility there is some kinda download accelerator plugin you have in Firefox that is conflicting with the vizzed plugin.