W10: Drag&Drop not working from host to guest

[DeGarcen]

Have Windows 10 1909 on both host and guest, Virtualbox 6.1.6. Guest with GAs.

Drag file from host to guest: not working (displays the forbidden symbols on mouse pointer).
Drag file from guest to host: works.
Copy and paste text to clipboard does work on both directions.

[DeGarcen]

Logs attached.
Edited later: removed VBoxHardening.log.zip

[scottgus1]

One point about the hardening log: If you scroll to the very bottom and see:

ExitCode=0x0

then you don't have a hardening problem and don't need to post the hardening log.

From the box.log I see that you have the matching version of Virtualbox and Guest Additions, good. Drag-n-Drop is set to bi-directional. I see mention of Seamless in the log. Did you have your guest Seamless when trying Drag-n-Drop? If so I wonder if Seamless' transparent desktop might interfere with Drag-n-Drop?

An aside on Drag-n-drop: I have had guests lock up during a failed Drag-n-Drop, with the only solution to kill the guest unceremoniously. Fortunately I did not have important unsaved data open at the time. Suffice it to say I don't trust Drag-n-drop, and the Guest Additions Shared Folders have always been reliable.

On another side you have all four physical cores set for possible use in the guest. Extra cores make the guest run slower, due to extra scheduling overhead on the host. Additionally, if the guest goes to 100% on all four cores the host could go unstable. Windows 10 happily enjoys 2 cores.

[DeGarcen]

One point about the hardening log: If you scroll to the very bottom and see:

ExitCode=0x0

then you don't have a hardening problem and don't need to post the hardening log.

From the box.log I see that you have the matching version of Virtualbox and Guest Additions, good. Drag-n-Drop is set to bi-directional. I see mention of Seamless in the log. Did you have your guest Seamless when trying Drag-n-Drop? If so I wonder if Seamless' transparent desktop might interfere with Drag-n-Drop?

An aside on Drag-n-drop: I have had guests lock up during a failed Drag-n-Drop, with the only solution to kill the guest unceremoniously. Fortunately I did not have important unsaved data open at the time. Suffice it to say I don't trust Drag-n-drop, and the Guest Additions Shared Folders have always been reliable.

On another side you have all four physical cores set for possible use in the guest. Extra cores make the guest run slower, due to extra scheduling overhead on the host. Additionally, if the guest goes to 100% on all four cores the host could go unstable. Windows 10 happily enjoys 2 cores.

I've tried with and without Seamless mode, and doesn't work with either of them. You say that there's mention to Seamless in the log, and that's true, it says there's capability to do that, but is not activated.

[DeGarcen]

Also copy and paste files (CTRL+C, CTRL+V) doesn't work on either direction.

[DeGarcen]

Performed more tests. Followed this guide and used setx on both host and guest: Investigating drag and drop (DnD) problems
The results are as follows: When performing copy from guest to host, VBox.log on host registers the file operation successfully. Howver when I drag another file from host to guest it just displays the forbidden symbol, and on VBox.log there is no mention to such file under "DnD:" or any other place. The guest has the file "C:\VBoxTray.log" but it only has 7 lines and nothing mentioning any file.

New log attached.