Covered here: https://wyday.com/forum/t/4205/current-limelm-server-status/#post-19954
Read the error code for how to use the web API: https://wyday.com/limelm/help/api/limelm.pkey.generate/#error-codes
1. Create a separate user for every server you're using a web API key on.
2. Only use web API keys from static servers.
3. Never embed web API keys in client-side JS or in your app.
Also, FastSpring uses a single outgoing IP address. So, ensure your web API key has not been compromised (if so, generate a new one), and only use that web API key from FastSpring.