I spent some time researching this and found that for the past several years users have been experiencing this sort of randomly. One of the things that sometimes worked was Trudy's suggestion about clearing the cache. The other thing that some users found was that whatever the display options/search filters were set to in the main Bridge window, would randomly change, which explains the "no items to display" part. I wasn't able to find where specifically to look for those settings. It also seems that the problem happens most often when the files are on an external drive.
Sorry to not be of more help ... what a frustrating problem!