Following this link on github, I have discovered to have the same issue as another user with my old version of JabRef. So I downloaded the new version, but apparently here I am not able to drag and drop anymore.
Copying my post there,
[…]I don’t know what is the “main table” apparently:
Dropping on the main table will try to create an entry from the pdf.
Dragging on the entry preview or general tab should move the file to the file dir
Where should I drop the file? It only accept it on an existing article entries, and it merely links that entry with a copy created in the Jabref folder (it does not even ask to rename the file, I loved that option).
I played a bit with it to see if anything has changed. Sadly, it seems to behave erratically.
Sometimes I manage to add a link to the pdf! into the entry, but it does not fill the data.
Sometimes (once) it fills the data, but it does not copy the pdf in my Bibliography folder.
Sometimes it create a file called “-.pdf” in my Bibliography folder, which is the exact copy of the article I dragged. I assume this happens because it does not fill the data, so the article is named “-” instead of “noname”.
Edit: update
THIS IS NOT TRUE → When it does, it adds an error :
apparently, the error appears randomly
Uncaught exception occurred in Thread[JavaFX Application Thread,5,main]
Flush is forbidden from target!
The exception stacktrace was
java.lang.UnsupportedOperationException: Flush is forbidden from target!
at org.jabref.merged.module/com.sun.glass.ui.View$2.flush(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.QuantumClipboard.flush(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.QuantumToolkit.startDrag(Unknown Source)
at org.jabref.merged.module/javafx.scene.Scene$DnDGesture.dragDetectedProcessed(Unknown Source)
at org.jabref.merged.module/javafx.scene.Scene$DnDGesture.process(Unknown Source)
at org.jabref.merged.module/javafx.scene.Scene$MouseHandler.process(Unknown Source)
at org.jabref.merged.module/javafx.scene.Scene.processMouseEvent(Unknown Source)
at org.jabref.merged.module/javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.View.notifyMouse(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.mac.MacView.notifyMouse(Unknown Source)