Di1997 :
Before i was able to open server, and make my friends/other people connect to it. Untill my ip changed. I didn't change anything. Ip was the same. Now i can't open server that will make my friends connect to it
Unless you are paying for a static IP address through your provider, it's normal for an IP address to change on occasion.
You'll just need to provide your friends the new IP address, get a static IP address from your provider, or use a dynamic DNS service.