Before switching to Joplin I used Evernote. I normally scan documents to pdf and these pdfs where added to Evernote, one scan one note.
With Joplin I have to do this manually. So, I dicided to summerize some note to one.
Before
note A with attachment A
note B with attachment B
note C with attachment C
Now
Note with attachment A, B, C
I copied (sometimes I maybe used cut and paste) the whole link from the notes B und C to the summary-note A. After copying I deleted the old note B and C.
Now, the attachments from B and C are gone. I get the little J-Icon and can not open the attachments. Attachment A is still there.
This is a big problem. I lost so many important documents. I am desperate. I have backups but I use Joplin since more than two years. I can not recover every attachment.
Check if they are in your resource folder or not. The attachment markdown should look like [AttachmentName](:/0c993a43c13346fdba587bf5ca507017) and that id should correspond to a file in your resources directory (i.e. .config/joplin-desktop/resources) (click help > open profile directory if you don't know where it is)
The attachments are gone. I just open joplin on another device. It starts to delete more than 100 resources that are still in use. I found the ressources in old time machine backups.
Then I assume they are missing from your sync target for some reason and Joplin is reflecting the deletion of them. I assume your latest backup would have all your old resources stored?
I think, this is a serious bug. Joplin thinks the ressources aren't in use after I copied them to the new note and remove the old note. I do this since a few months. So I have to search through many backups. This is a nightmare.
Before we go that far could you explain exactly what you did?
Did you just copy the markdown tag with resource id (like I posted before) between notes? Or something else?
Yes, if you had a note with a picture and you then deleted that picture entirely with no other notes referencing it then wouldn't you expect the attachment to be deleted? The note history setting would preserve it until the note revisions themselves are deleted at which point nothing else in the database references it.
In your case it doesn't sound like it should be applicable because you have a reference to that attachment in another note.
Joplin copies with full absolute path if you do copy and paste using the visual editor. This is a bug and completely wrong way to handle internal copy pasting of images. I reported this already. You might be hitting this one.