Purchased Rise of the runelords but none of the character sheets are filled out.

None of the sheets have anything in them! They're all blanks with nothing filled in!

Which ones are not filled out? IIRC, there were background NPCs that only had handouts, but everything else had a statblock.

Some of the more import ones I even checked the final boss and he was a new sheet . I suppose it did 75% of the work for me so if I have to do the rest... Could it be something in the choice of sheet?

Possibly. The modules are designed to be used with the the official sheets created and maintained by Roll20. The module is designed to be used with the Pathfinder by Roll20 character sheet, according to the Marketplace page. This is true of all licensed material released by Roll20. (I.e. they are built with Roll20 sheets in mind.) If this is not the sheet your game uses, I would suggest creating a new game from scratch with the official sheet, rather than converting the existing one.