I have my photographs all ready to export in Lightroom 2. When I go to Library - Export and select All, it asks me to select a file, size, etc. which I did. But when I hit Export it tells me the files cannot be found! On the side bar next to the file name, there is a small question mark (?) - never saw that before. Any suggestions on what may be preventing the files to be 'found' and 'exported'. ? Thank you
This means that Lightroom cannot find the files, they have been renamed or moved or deleted outside of Lightroom.
You need to use your operating system's search feature to search all hard disks for a file with the name of the file you are trying to export. Once you find it, you can reconnect the files to Lightroom by following thse instructions: http://www.computer-darkroom.com/lr2_find_folder/find-folder-old.htm
That means you have somehow managed to loose the link between the photos and Lightroom.
Have you moved the photos or renamed them outside LR, or are they on an external drive which is not connected?