Ports refuse to open

[Svenren]

I'm trying to open a couple of ports for my emulator in order to host. For some odd reason however the ports won't open even though port forwarding worked fine in the past.

I assigned my pc as a DMZ host on my router and the router as a dmz host on my modem, I've had this set up for quite a while and it worked. But now it refuses to work and not a single port will open. How would I fix this?

 

[failboat]

Did you update your router recently? They might of patched these security leaks.
Opening all your ports using "dmz host" is very insecure.

search for the ports you need and port forward them correctly.