Can't connect to server

Hi!
I’m start learning network and trying simple function.
when i try connect to server i have an error:
NAT target 77 not connected to NAT facilitator 67.225.180.24:50005

How can i fix this?

Can you post more about what you are doing?

I appreciate the error, but we would need to know what you are doing to get there! (~.^)

Some sample code and links to the pages you are using for reference would be best.