Hi Barbarossa49,
It sounds like a port issue. Its possible that if you have a router that was previously configured correctly, the internal IP or LAN IP that you set up the ports to map to has changed. Quite common issue. Be sure that the IP used in the router/modem configuration is still the correct one.
Here are instructions for getting that info if you need it.
https://www.winmxworld.com/tutorials/routers_info.htmlIts also possible that your ports may have been changed in WinMX and are different now from the ones you have configured in any router, modem. or firewalls. Be sure those are still matching what you had set before. WinMX > Settings > Incoming TCP and In/Out UDP.
If your still having issues after checking these things could you post back what router and/or DSL modem your using?
What firewalls?
Any changes you've made recently.