VBoxClient does not work after upgrade to 20.04 LTS Beta

[fas-ubuntu]

I run Ubuntu Studio 18.04 in VirtualBox VM.
I did a upgrade to 19.10 and then to 20.04 (development)
VirtualBox guest additions were installed via apt.

1) lsb_release -rd
Description: Ubuntu Focal Fossa (development branch)
Release: 20.04

2)
virtualbox-guest-x11:
  Installed: 6.1.4-dfsg-2
  Candidate: 6.1.4-dfsg-2
  Version table:
 *** 6.1.4-dfsg-2 500
        500 http://de.archive.ubuntu.com/ubuntu focal/multiverse amd64 Packages
        100 /var/lib/dpkg/status

virtualbox-guest-dkms:
  Installed: 6.1.4-dfsg-2
  Candidate: 6.1.4-dfsg-2
  Version table:
 *** 6.1.4-dfsg-2 500
        500 http://de.archive.ubuntu.com/ubuntu focal/multiverse amd64 Packages
        500 http://de.archive.ubuntu.com/ubuntu focal/multiverse i386 Packages
        100 /var/lib/dpkg/status

3) What I expect:
Copy-and-paste to work as before on 18.04.

4) What happened instead:
It does not work. Even after purging and reinstalling it with apt.

Related error messages on first reboot:
"VBoxCliebt crashed with SIGSEGV in XQueryExtension()"

and in /var/log:
ERROR: apport (pid 1626) Wed Apr 8 16:33:04 2020: executable: /usr/bin/VBoxClient (command line "/usr/bin/VBoxClient --vmsvga-x11")

[fas-ubuntu (fas-ubuntu)]

This may be moved to another package but I found it when proceeding with https://iso.qa.ubuntu.com/qatracker/milestones/408/builds/210101/testcases/1310/results

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1871658

[Erich Eickmeyer (eeickmeyer)]

This is a bug in Virtualbox 6.1.4, not the release upgrader.

[Gianfranco Costamagna (costamagnagianfranco)]

please try again with 6.1.6, thanks

[fas-ubuntu (fas-ubuntu)]

Hi Gianfranco,

installed 6.1.6

shared clip board still not working

[Launchpad Janitor (janitor)]

[Expired for virtualbox (Ubuntu) because there has been no activity for 60 days.]