Yes, if you could provide the name of the game, answering this question would be easier
However, for what you're saying, I have the feeling you might be referring to Last Stand Dead Zone. If that's the case, you should check the support section of the ConArtist forums.
The answers I've found so far are that a) these MMO game servers seem to go down quite a bit, as such things go and will and do happen; b) however, it pays to check all your finer settings, including any ad blockers and the likes you may have running, as to the allowances you give JavaScript and/or Java (and FlashPlayer and the likes), which you'll need to allow both for this site, and whatever third-party sites those MMO games may actually be hosted on. (It follows that I reckon there's not a lot ArmorGames can do about it if they do go down, other than cross their fingers just like the rest of us. If and when indeed those games aren't hosted by AG. You could of course contact the admins of the appropriate sites, if you can figure out which they are.)
I (or others, no doubt) can check what sites I think need to be allowed to play your game, but only if you tell us what game it is.
Hmmm, and sorry for the cross-post above, I guess it's just like that so long as there's no option to edit one's posts later.
I have a feeling a while ago I did look up for someone what servers to allow JavaScript and (consequently) FlashPlayer for to play Last Stand here; but for lack of a forum search function, to find it back in a jiffy seems a little daunting.
(I tried the "unofficial" search function, but doesn't seem to work for me. Must be blocking something, indeed! )
The solution I found did work for me, but not being a player of the game, I'd need to retrace what steps I followed. It's just allowing whatever servers the game runs on, indeed, two of them if I recall. You can weed them out using NoScript in Firefox, which in my case is of course what blocks them, so all you need to do is unblock those.
(However, not using such an ad or script blocker, they may still get blocked by other settinsg elsewhere in your browser or system, which may then however be much harder to pinpoint.)