New to forge, having issues with themes and tokens.

Hello all! I'm new to Forge, and despite my best efforts to resolve the problem myself with the use of the search function, I haven't had any luck. I'd really appreciate if someone with a little more know-how could help me out with two particular issues I'm having.
The first, it seems like I'm not able to use custom themes within the client. I've downloaded a few found on the boards here, and extracted them to my MTG Forge\res\skins folder, but I get a crash whenever I try to select them in game.
The second, I was wondering how I would go about changing/adding token images. From what I've gathered trying to figure this out on my own, I'd need to change the images in the token folder, but I was wondering if this had to be done on a card-by-card basis. For example, if I change the zombie tokens created by diregraf colossus, would it have any effect on the tokens created by, say, dark salvation?
If it helps, I'm using the latest snapshot build, and while I originally was getting error messages for the crashes when I attempted to swap themes, I no longer do, so I'm unable to post them here.
The first, it seems like I'm not able to use custom themes within the client. I've downloaded a few found on the boards here, and extracted them to my MTG Forge\res\skins folder, but I get a crash whenever I try to select them in game.
The second, I was wondering how I would go about changing/adding token images. From what I've gathered trying to figure this out on my own, I'd need to change the images in the token folder, but I was wondering if this had to be done on a card-by-card basis. For example, if I change the zombie tokens created by diregraf colossus, would it have any effect on the tokens created by, say, dark salvation?
If it helps, I'm using the latest snapshot build, and while I originally was getting error messages for the crashes when I attempted to swap themes, I no longer do, so I'm unable to post them here.