Shared clipboard is not working in headless mode

[Suncatcher]

I've found plenty similar tickets about this issue but they all are related to obsolete versions so I created this one.

Several tickets (14964, 14645 and 14421) are likely to be the same (I don't know this for sure) but there was no mention about headless mode or VRDP and my tests clearly say this is headless-only bug. The most appropriate recent tickets I found were 11937 and 10057 (which are still open), but there are much-much older ones (11140, 3794)

I decided to create my own as I don't know exactly is my issue related to any of them so it's up to admins to merge them or leave them as is.

All in all, my bug comprises several symptoms:

1. shared clipboard does not work guest2host direction on Windows and Linux guest.
2. shared clipboard does not work inside Windows guest at all (in Linux guest does)
3. All this is observed only in headless mode (guest is accessed via VRDP).

Host2guest direction works good. In GUI mode both directions work wonderful.

[Suncatcher]

windows_guest_logs

[Suncatcher]

linux_guest_logs

[dkjprog]

I am having a similar problem in Version 5.1.14 r112924 (Qt5.6.2):

1. kubuntu 16.04 guest
2. windows 7 host

Shared clipboard works find in both directions natively (i.e., when using the Virtualbox GUI directly), but in headless mode, using RDP, copying from guest to host fails. Host to guest works fine in both GUI and headless/RDP modes. NOTE: If I try and copy from guest to host w/RDP, which fails, and then revert back to GUI mode, copying from guest to host is now broken also -- as if attempting it w/RDP changed something in the guest itself. Rebooting the guest is the only way to restore guest-to-host copy/paste in GUI mode.

[Socratis]

According to Suncatcher_13's further investigation (​https://forums.virtualbox.org/viewtopic.php?f=6&t=80793):

Well, I finally figured out the problem. I apologize and have to admit the problem isn't in Virtualbox, but it's rather a Windows limitation. Windows cannot share clipboard if more than one RDP-connection is active . It was proven during my extensive tests with all types of machines (Linux and Windows). It is also true for any client, I tested both native Windows RDP client and alternative ones (Parallels). That was my fault and that is the thing I never payed attention before that: I mostly used 2 RDP connections simultaneously and that was the pitfall, clipboard was blocked because of this fact and didn't function both inside guest and outside too. Will submit this issue to MS.

@dkjprog:
Please check out the discussion that I linked to above and see if there is anything there that can help you.

[dkjprog]

@Suncatcher_13 Thank you! I will check it out.

[dkjprog]

@Suncatcher_13, I posted a reply to yours in that forum thread.

[johny_mnemonic]

I can confirm the behavior reported by dkjprog in first comment and I have also added more details to the forum thead: ​https://forums.virtualbox.org/viewtopic.php?f=6&t=80793&p=387307#p387307

[Anderson M. Gomes]

I am experiencing this issue in my system. Shared clipboard works only if I start the virtual machine in "Normal" mode. It doesn't work if VM starts in "Detachable" mode.

• Host: Arch Linux 64 bits
• Guest: Windows 7 64 bits
• VirtualBox: 5.1.22r115126

[rdol]

I can also confirm the same findings documented by dkjprog. Host: Windows 10 Pro build 1803 x64 Guest: Windows 10 Home build 1803 x64 VirtualBox: 5.2.20

I can also confirm the clipboard works fine between multiple RDP sessions. I work with Remote Desktop Manager with many RDP sessions opened at once almost all the day and clipboard works as expected.

Any chance to prioritize this bug? It's definitely inside VirtualBox, not in Windows.