My approach (FWIW) is to do the main organization in my windows file system. Each “dump” of files from a camera SD card goes into a folder labelled with date, camera, and main event/subject.
In dt, I simply import the folders and rate the images, then after processing all the 2-3 stars (depends) or better images, they get exported as jpgs in a suitable size for sharing to a subfolder inside the folder of images.
I very rarely have any issues, but maybe I’m just not ambitious with organization… 
Yes, I checked the file in my OS and xmp files are there.
Perhaps you have some filtering in place. Try clearing all filters
I imported and added my new raw files to the library, rated them and opened one in Darkroom. I made several adjustments and moved on to another image. After editing three or four I could still go back and see the previously edited images with all the edits. At the end of the session I simply quit DT. This morning I went back in and all the edited images aren’t available. I was expecting to see the thumbnails at the cropped size. I checked this morning and xmp files are with all the photos but changes I made yesterday aren’t.
Yeah I also just put them in folders with the data and event/model name and then I star the images I want to develop, filter them, so only those get shown, edit, export, done
Version 4.2.0.
Are you using grouping? And are you perhaps editing the jpegs instead of the raws? Just asking, stupid things happen 
I don’t think I’m editing jpegs as I have the don’t show jpegs box ticked. I’m not using grouping at least not on purpose.
That’s more or less what I do expect yesterday I didn’t export the finished raw files. I thought I would do that this morning but they’re not showing.
Thanks, I did that but they’re still not showing.
Do you mean that your raw files aren’t showing, or that just the edits are missing?
And how exactly did you install darktable? If it’s a flatpak install, that might be the problem, given
this thread.
And can you re-import the images in dt? The edits should show after re-import.
Edits are missing or I don’t see the edits. Raw files seem to be there. I’ve tried re-importing but it doesn’t help.
I don’t remember if it was a flatpak but it very well might be. I’ve used it for other apps and have had some problems when I do.
Maybe uninstall reinstall is the answer.
When you say you did some rating…as someone mentioned are you sure you are not filtering at a certain rating . I think if you go to the folder and attempt to import… you should see one of two things…the files will be part of a the list without checkmarks ie not yet imported or they will have checkmarks indicating they are imported as as DT thinks anyway…so now if you cannot see them it would seem like filtering might be a good explanation…
'twas I.
And filtering is frankly bewildering now. I’m with Aurelian on this.
The old widgets are still there, just enable them.
1- Make sure you have a collection selected
2- Clear Filters
3- Keep an eye on this widget
If it’s on the 4th icon and no images are selected, the screen is empty. Tripped over it before.
I don’t think I’m filtering but I certainly could be missing something. I’ve tried turning all filters off and looking for different ratings, re-importing.
Today I installed Digikam to give it a whirl and the missing images didn’t turn up when the import happened. Maybe they really are gone somehow.
I’m going to try a different workflow where I export a copy of the raw file to another folder. It’ll take up some space but that’s OK.
In general, when I’m in digiKam, I open my RAW files in RawTherapee. I’ve personally never tried out Lighttable, though.
That usually doesn’t do much as if you do, all your library, settings etc. are preserved in your config folder.
You could always just rename your config folder to make dt create a new one. If dt was set to write xmp files (sidecars) you will still have your edits when you re-import them.
I’m going to stick with DT so I processed those missing images again. I must have deleted them somehow. Oh well.