Difficulté à transférer Lightroom Classic sur une nouvelle machine

Translation to English:

Lightroom  refuses to open these images in another application.

I restarted the computer and currently all the photos can no longer be opened.

So I assume that this means your catalog itself was working and you could edit in Lightroom Classic (not Lightroom as you said). But you didn't say this. Is my assumption correct?

After you restarted the computer, you said all the photos can no longer be opened, do you mean that now Lightroom Classic cannot edit the photos? Or do you mean that you still can't open the photos in the external applications such as Topaz? If so, you need to explain in detail exactly what happens when you try. (And also, what do you mean by "open", as LrC does not "open" photos)

Are there exclamation point icons on your photos as shown in Figure 2 here? Are there question mark icons on your folders as shown in Figure 3 at the same link?

 

Bonjour,

 

J'ai exporté mon catalogue sur un disque externe. J'ai installé Lightroom sur le nouvel appareil et j'ai importé le catalogue.

By @gaetan-julienf92464951

Translation:

I exported my catalog to an external drive. I installed Lightroom on the new device and imported the catalog.

What do you mean with exported to an external drive and later with imported the catalog?

If you like to move a catalog to another location (in your case to a external drive) the easiest (and best) way is to copy the catalog file to the appropriate drive. Make sure that the name of the drive and the folder structure of the location where your images resides doesn't change. Then open the catalog from the new location and all should work.

How do I find and move or rename my catalog? | The Lightroom Queen