time capsule only backs up current month and the rest are purpled out and inaccessible. Why?

My Time Capsule is only backing up the current month and the rest of the backups are purpled out and inaccessable. Can someone tell me why this is and if there is a fix for it? I have an early 2012 MacBook Pro 2.4GHz Core i7 8GB RAM 170GB HD. There were question marks in my task bar of the Finder windows but I was able to get rid of those. Don't know if this is all related. My Time Capsule is 4th Gen and has a 3TB HD.