'vagrant up' fails with Vagrant::Errors::VirtualBoxUserMismatch

[James E Keenan]

I am encountering an ERROR in 'vagrant up' when I try to boot a
'generic/openbsd7' (virtualbox) VM obtained here:
https://app.vagrantup.com/generic/boxes/openbsd7/versions/4.0.2

I have installed 'generic/openbsd*' VMs from app.vagrantup.com several
times previously on this FreeBSD-12 host, most recently for OpenBSD-6.9.
The installations were smooth, so I am surprised at the problem I am
experiencing.

Here is partial output from 'vagrant up --debug':

#####
INFO loader: Set "2580_machine_default" = []
INFO loader: Loading configuration in order: [:home, :root,
"2580_machine_default"]
ERROR loader: Unknown config sources:
[:"2720_generic/openbsd7_virtualbox", :"2580_vm_default_generi
c/openbsd7_virtualbox"]
DEBUG loader: Loading from: root (cache)
DEBUG loader: Configuration loaded successfully, finalizing and returning
...
/usr/local/lib/ruby/gems/2.7/gems/vagrant-2.2.14/lib/vagrant/environment.rb:290:in
`cli'
/usr/local/lib/ruby/gems/2.7/gems/vagrant-2.2.14/bin/vagrant:210:in
`<top (required)>'
/usr/local/bin/vagrant:23:in `load'
/usr/local/bin/vagrant:23:in `<main>'
INFO interface: error: The VirtualBox VM was created with a user that
doesn't match the
current user running Vagrant. VirtualBox requires that the same user
be used to manage the VM that was created. Please re-run Vagrant with
that user. This is not a Vagrant issue.

The UID used to create the VM was:
Your UID is: [XXXX]
The VirtualBox VM was created with a user that doesn't match the
current user running Vagrant. VirtualBox requires that the same user
be used to manage the VM that was created. Please re-run Vagrant with
that user. This is not a Vagrant issue.
...
INFO interface: Machine: error-exit
["Vagrant::Errors::VirtualBoxUserMismatch"
#####

Comments:

1. The ultimate error is the alleged UID mismatch at the bottom of the
output above. I don't know whether the 'ERROR loader' output above is
relevant or connected to the ultimate failure.

2. The UID elided at XXXX above is the correct UID for the user with
which I always execute 'vagrant' commands.

3. Note that there is no output next to "The UID used to create the VM
was: ". Why would 'vagrant' be unable to detect the "UID used to create
the VM"?

Has anyone seen this problem before? Any suggestions?

Thank you very much.
James Keenan