Connection Problem: Server doesn't respons

When using the same connection settings I had successfully used for the last month I now get an error within the YouTrack Workflow Editor app that states the following:

Connection Problem
Server doesn't respond
Check your Connection settings

I've double checked the information, made sure my password was correct and everything and still I get this error. Has anyone had a similar problem or does anyone have any ideas on how it might be resolved? Thanks

Chris