Frequent Advisor
Sprint Backlog - No Active Members for this Sprint

I've seen this frequently but I don't know why. 

 

I am in Sprint Planning and I can't seem to move from Sprint to Sprint - it is greyed out.  And it also tells me "There are no active members for this sprint" - screen print is attached. 

 

What is the cause of this?  How to I stop if from happening? Is this a Defect?

 

After I move around in AGM for a bit, I go back and the members are there - did I do something to make it change?

 

Thanks in advance...Deb