Our office worked on a large shopping complex and started on AC 6.5, upgraded to 7.0 and then 8.1... a very long project. To update you can either select the pmk on your screen, right click and select update (this is on PC, not sure if you running Mac or not). It'll update to your most recent version of that pmk of that name in the allocated folder. You could also click the 'tree by subsets tab' in the navigator toolbox. Select 'drawing usage' and here you'll be able to edit the path of the file or update it.
