A welcome return - but I'm wondering why Firefox now insists on telling me that this is a risky site?
If you mean the little padlock with a line through it then that is because the connection between your browser and the site server is not protected as the traffic is via HTTP not the more secure HTTPS. Firefox is letting you know and has been doing this by default for a little while now I believe.
You'll find most modern websites now use HTTPS, generally for reasons that are of benefit to everyone including security. If someone is hoovering up traffic on an unprotected (i.e. HTTP) website to try to identify user specific info they can see anything entered by users as the traffic is all in plain text, e.g. password on a login page. So if you are using a site like this that is still HTTP then make sure you don't use a password that is the same as your banking/amazon/.gov etc. sites. But you knew that anyway...
If it is some other message from Firefox then I don't know Chris. Post an image.