I would like to help but don't quite understand.
If the jpg is visible in the library, LR know where the folder and file are unless there has been a change.
When you use the Folders pane to find a .jpg, is there a "?" displayed?
no, there was no "?" displayed, all looks normal... but in just the develop screen it was a big grey blank, and 'folder could not be found".... in frustration last night i closed everything down and today simply re-booted the entire computer and my mystery is this morning i can see the jpeg..... i may never know what caused the glitch... is it therefore a good idea to re-boot the HD after making changes like adding LR5??? Does LR5 need that to properly interface with other files/folders on a HD?? it would help to know before i add LR to my ultrabook!! thanks so much for being available to all of us 'beginners'!!
If you have trouble with applications after installing it is usually a good idea to restart. If you continue to have problems after restarting however, that would be a reason to worry.
I'm getting this figured out! a big thanks for being available with tips and reading other posts is very useful! thanx again!