Simple cycle problem

Hi there

I have a issue with creating cycles. I have been following the toonboom animate 3 documentation on creating cycles:

http://docs.toonboom.com/help/animate/#HAR/Stage/007_Timing/085_H2_Creating_Cycles.html?Highlight=loop

However once i have select the cells I wish to cycle and go to Edit > copy the copy option is greyed out. Because of that I can’t go any further. I don’t understand why this is happening, It seems simple. Any Ideas guys?