The Fortress creation option would be there for the Marshal, so if you are the Marshal it should allow you and it should get built. Also as far as i remember the quest should be to visit the fortress or send reinforcement to the fortress.

It would help if you could share more details like the name of you league or the steps you are doing to built the fortress.

darylshinn said:

I have tried several times to build a league fortress, I go through all the steps it ask for and when i am done it says fortress being built, however no fortress is built and i still have it on the quest log 

Greetings m'lord!

As Lord Warrior has already mentioned, only the Marshal is able to create the fortress. However, there's more important points that apply before creating a fortress. You can find some information on the wiki, I'll describe them directly here as well for you;

• If you recently created your League, you'll have to wait 7 days after League creation until you're able to build your fortress.
• As already mentioned twice, you must be the League Marshal in order to do so.

It seems that it's a bug, please inform the Support Team!