No actions available to convert phone call to opportunity

i am working on customizing the phone call form, i clone an existing one and just rearrange the fields in the screen. 

i am using it fin and use to be able to convert any call to case or opportunity from the convert to menu after saving the phone call.

lately the convert to menu is showing (No actions available), i try to reverse all action i think about, but it is still not showing, what could went wrong to make it disappear, and how i can bring it back?