Unable to join any server

After a while of not playing DST , I came back and current having this weird connection error. I can't connect to any server / my friends can't connect to my server ( neither joining by steam shift+tab nor by in-game lobby worked ) and a window pops up saying "Server is not responding" 
I have tried every solution such as turning off firewall , disabling mods , port forwarding and running dontstarve_dedicated_server_nullrenderer / dontstarve_steam as an adminstrator , etc. But none of them fixed the problem for me , any help is appreciated and excuse me for my bad english