Lightroom Classic losing files

[XrayHuff]

I have been a Lightroom user for several years.  I got a new desktop computer and had it set up by a professional.  I have several problems with LrC, but the BIG one is that the new photos I have put in since the computer upgrade are losing the files after about a day.  In other words, I click on the preview, and  it comes up a little blurry.  Then I click Develop, and it says "The file could not be found."  Does anyone know how to fix this?

[Rob_Cullen]

Is there any chance your photos are being saved in Windows One-Drive?

Is LrC reporting your images as 'Missing'. Run the 'Find all Missing Photos' action from Menu: Library > Find all Missing Photos.

Did your "professional"  fuly understand the links between Catalog and photos that Lr-Classic requires?

[richardplondon]

That occurred to me too. Often this is because a destination within the "Pictures" folder has been chosen for imports (which is the, longstanding, default for Lightroom), and also because Windows' question "backup your files to cloud?" has been answered Yes.

OneDrive fthen moves everything from "c:\users\[user]\Pictures" (etc) into c:\users\[user]\onedrive\pictures" (etc).

Also, these files are no longer unconditionally present in the computer locally - since that now depends on the moment-to-moment storage management whims of OneDrive, behind the scenes.

Any of these files will report for duty if explicitly opened (e.g. into Photoshop) - getting re-downloaded from cloud as necessary. But the LrC Catalog expects all images to be "on active standby" constantly, and without needing to actively open every one. So OneDrive hears no such request, thinks it's OK to dynamically regain that local disk space, and then the Catalog sees these are physically absent from local disk. 

My suggestion is either: change the OneDrive settings for these special folders (such as Pictures), to make sure a local copy of everything will be permanently there - or, better IMO, to avoid using e.g. "Pictures" for files that are imported. And in any case to avoid using "Pictures" for storing the Lightroom Classic Catalog itself.

Then the whole complication of OneDrive goes away so far as LrC is concerned. You can still of course export images into Pictures where they will be included in your cloud backups by OneDrive.

Note: backing-up the LrC imported images (and the Catalog) will then be up to you to make happen by other means.

[AxelMatt]

Do you have still access to your old computer?

If yes, you can check where the now missing pictures are located and transfered it to you new desktop.

[dj_paige]

Sounds to me like the previews are where LrC expects them to be, but the original photos are not where LrC expects them to be. First you need to find the place on your computer or external drives where your professional actually put the original photo files. Then you need to follow the instructions here carefully, especially FIgure 4 which lets you re-connect a whole "tree" of folders at once.