What platform are you using (Windows, Mac)? Do you have WebDirect enabled under the Web Publishing tab? Did you get any error messages about web services when you started FMS?
Sorry for all the questions, but it will help in diagnosis.
I'm on an iMac. It's running FM server 13. WebDirect is not enabled on the admin status. I haven't gotten any errors, but I can't figure out how to turn WebDirect on. Thanks for your interest.
Try redeployment to see if it enables it again.
I apologize if you have already done these steps.
Open FMS admin.
Click on Web Publishing on the left.
Choose FileMaker WebDirect tab in the main section of the window.
Ensure that the Enable FileMaker WebDirect box is checked.
If you cannot get to the Web Publishing area, look at the Web Publising Engine area of the Status page. Make sure the web publishing engine has a green check mark next to it. If not, try clicking the "power button" icon in the top right corner of the box. (Looks like a gray circle when off and a blue and white 1 when on.)
If that doesn't work, it seems likely you did not include web publishing when you deployed the server. You'll need to redeploy as PowerSlave said above.
Did it work sometime?
If it was working and now is not, you can do this on Terminal:
sudo apachectl stop
Type your admin password and hit ENTER.
sudo /Library/Filemaker\ Server/HTTPServer/bin/httpdctl graceful
And hit ENTER.
Try again after that.