I made Vietnam a playable nation, and all the players value is stuck at - and I am not sure how to fix it. I have made Vietnam a playable nation in 2012 and the player value actually goes up and down.
Players have no value if they're not tied down to full-time contracts and maybe even part-time ones, though I'm not too sure on that. Non-contract and amateur players have no value and so often they'll get poached.
Could that be the reason to your problem?