Forum

I have set up several courses within our moodle system, but recently, I set up a new course like all the others and when I opened the course page, instead of seeing the usual "add new topic forum", its said:

That forum type doesn't exist!

Could not find or create a social forum here

Why is this happening and how do I correct it?  I set it up identically as the others and didn't see this happen with them.  Any assistance will be appreciated, this is for a course that starts soon, so I hope someone can help shortly.

Thanks,

Vikki