Following a failure of a hard drive with only images on it I installed a new disk, with same drive letter, transferred my backups to the new drive and then redirected Lightroom to the new drive. I have a folder structure. In some cases folders were found and grid populated fine, but in other cases the images are all there but the folder is still grayed out with a question mark. LR doesn't appear to know where it is despite having gone there and correctly found the images in the folder. Any suggestions as to why this might have happened and how to get it to show the folder not grayed out? I have Windows & Professional.
I can only guess ... the folder structure did not match identically to what you had before the hard drive failure; and now some folders need to be reconnected in Lightroom individually
I did folders individually for the ones LR said were missing, and they stayed grayed out with question mark. Content shown correctly in LR however. I don't see why LR would load the files correctly and still say it can't see the folder they come from.