It seems that there are images missing in Lightroom, so I would suggest you to first find the missing images in Lightroom.
Please check the following link : Adobe Lightroom - Find moved or missing files and folders
I don't have ! nor ? and I don't store images off line so the tutorial was not helpful except that it suggested rummaging in Finder--at which point I don't need Lightroom. At some point with unknown keystrokes I found everything on each HD listed in the right column. I clicked a couple things I didn't understand because the name was truncated. Then all the files on this HD displayed on left column. I don't know why exactly because I cannot look at both edge columns at the same time. So, now I have folders--not the folders I want--in the left column where I've seen my photo folders before now I just have everything mixed up, for instance: Lightroom 6.4.0 update with a subfolder "? RAW." Is that an update I need to install? Is it an image? Why then would it be here if not a folder of images? Nothing happens when I click it.
All I want out of LR is a filing cabinet. Arranging a new workflow around an application that doesn't give me a product is a waste of my time. So how do I get there?
Then you should have a better idea of what is happening where and when.
It is a good idea to know where you are headed before you set off as it is easy to end up in the where you don't want to be or where you don't know where you are..
Once I got that out of the way, I could not find my collections. Everything was gone from left column.
This could indicate you have opened the wrong catalog (perhaps accidentally) and you should use the Lightroom menu command File->Open Recent and select each catalog listed there to see if your collections appear.
NOTE: This does not explain your other symptoms, which indicate different issues. Try the suggestion above first.
Tried that. no results. No doubt, I'm in a screen I don't understand but doesn't really matter--an unpredictable product is Adobe's problem. My workaround is Bridge which is working fine. Called Adobe, told by a live paid human being that Adobe doesn't do phone support for Lightroom. He instructed me to watch countless videos starting from ideal conditions instead of what I have which is a nose dive so, kinda a waste, followed by six hours of crowd source support. So LR is out. Adobe.com/LR/suicideprevention
I really don't follow what your problem is or what you have done or are trying to do...... I guess you are on a Mac???
What have you done and what are you trying to do??
It sounds like your image files are not accessible to Lightroom so you need to establish where they are.
Thank you Geoff for your tenacity
I'm trying to stay organized but LR imposing too much complexity. When I import, I want to name a folder and click import. This is how Aperture worked. Too bad this is not Aperture. At my age I'm interested in things that simplify the life I have. I know my old images are in the same places as before. The question is what to do with LR and how to get the folders displaying in LR again and keep LR from going into unnecessary modes.
It really is that simple... look I'm almost at pension age and have a pretty well organised system using Lightroom on a Mac....
And I click Import and the files end up where I want them...
Look at this video about importing and organising