Decided Against put the twilight forest in the portal menu

I don't know why the twilight forest hasn't already been added to the portal menu>

 

It is added to the portal menu if your on a 1.7 server the Twilight Forest is disabled its only enabled on the 1.12 servers

 

oh lol why is it disabled on 1.7 servers

 

Cause the mod caused performance issues for servers in 1.7 but it was fixed when the mod was updated to 1.12

 

There are a few very broken things in 1.7.10 that you might even notice in single player. The bosses as Aidoneous points out are one of the issues, there is also an issue with I believe it was the way the dynamic environment works leading to sort of a cascade of loading chunks. Plus there are some rendering issues with clients in general in some of the areas, it is best left out.