Drag-and-drop problems with 5.0.18 and Ubuntu guest

[finnzk]

Since upgrading to 5.0.18, I've experienced a drag-and-drop issue on an OS X 10.11.4 host with Ubuntu 14.04.4 and Ubuntu 16.04 (currently, 4-20-2016 daily build) guests. Basically, if I drag a file onto the guest desktop, it doesn't appear, but *does* appear in "VirtualBox Dropped Files" in /tmp.

It should be very simple to replicate this problem (or disprove by showing that this is something local to my system):

1. Install a fresh Ubuntu 14.04.4 or 16.04 guest (8192MB Ram, 2 processors, drag-and-drop set to "host to guest"), update all of the packages, and install the 5.0.18 extensions. Reboot.

2. Try to drag a file from the host OS X 10.11.4 desktop to the guest desktop. Nothing appears. File *does* appear in a directory in the "VirtualBox Dropped Files" directory in /tmp.

Is anyone else seeing this behavior?

[finnzk]

A little more information:

I followed the instructions at:

https://www.virtualbox.org/wiki/DnDDebug

modifying the appropriate files and re-trying the drag-and-drop (with a single, small file from host-to-guest). The output of the log looks like this:

DnD: Proxy window=0x800001, root window=0x281 ...
02:59:24.136901 00007effb9fdd7c0 main DnD: Started
02:59:24.136907 00007effb9fdd7c0 main DnD: 5.0.18r106667
02:59:45.579806 00007effb9fdd7c0 main DnD: Entered new window 0x2e0000a ('Desktop'), supports Xdnd version=5
02:59:45.599885 00007effb9f5b700 dndX11 DnD: Target window 0x2e00161 ('nautilus') is asking for data as 'text/uri-list'
02:59:46.404693 00007effb9fdd7c0 main DnD: Drop event from host resuled in: VINF_SUCCESS
02:59:46.407118 00007effb9fdd7c0 main DnD: Received unsupported message: 210
02:59:46.407128 00007effb9fdd7c0 main DnD: Error processing message 210, failed with VERR_NOT_SUPPORTED, resetting all

Again, this is in a fresh Ubuntu 14.0.4.4 install (fully updated) on a Mac OS 10.11.4 host. Anyone know what might be going on here?

[loukingjr]

FWIW, disabling 3D acceleration will fix the drag n drop issue but of course the guest will be slower.

[finnzk]

That doesn't seem to be the problem. 3D acceleration was never enabled on this guest.

[loukingjr]

Sorry, I should have checked first.
It used to be the problem. Now it doesn't work even with 3D disabled.

[Tim Regen]

I reverted back to 5.0.16, reinstalled the guest additions and that resolved the issue.

[bigmidget]

I'm getting exact same error and issue in VirtualBox 5.0.26 r108824. Had this issue be resolved yet? Any workarounds other than downgrading version? I am running Windows 7 host and Linux Centos 6.7 guest.