Today I found out that Vagrant 2.2.7 has been released. A few weeks ago, the Oracle VirtualBox celebrated the release of 6.1.2. The thing with VirtualBox 6.1.2 was that it wasn't compatile with Vagrant 2.2.6, since that version of Vagrant lacked the support of the Virtualbox 6.1 base-release. It was solvable, as described by Tim Hall, with a solution of Simon Coter. Happily, as expected, Vagrant 2.2.7 supports 6.1.x now. So, I was eager to try that out. And it works indeed.

However, the first time I 'upped' a Vagrant project, I hit the error:

VBoxManage.exe: error: Unknown option: --clipboard

Sadly this was due to the following lines in my Vagrantfile:

    # Set clipboard and drag&drop bidirectional
    #vb.customize ["modifyvm", :id, "--clipboard", "bidirectional"]
    #vb.customize ["modifyvm", :id, "--draganddrop", "bidirectional"]

I did not try the --draganddrop option. But assumed that it would fail too. Commenting those out (as in the example) got my Vagrantfile ok again.
I use this to have bi-directional clipboard and draganddrop, which is off by default. So, I have to figure why this is.
After startup of the new VM, I tested the clipboard functionality and although these lines are commented out, it worked as such. Apparently I don't need those lines anymore.

Since it did not let me go, I tried:

C:\Program Files\Oracle\VirtualBox>vboxmanage modifyvm
Usage:

VBoxManage modifyvm         
                            [--name ]
                            [--groups , ...]
                            [--description ]
...
                            [--clipboard-mode disabled|hosttoguest|guesttohost|
                                              bidirectional]
                            [--draganddrop disabled|hosttoguest|guesttohost|
                                           bidirectional]

Apparently the the option changed to --clipboard-mode.