netplan apply and netplan try error

My server installation Ubuntu 20.04.3 LTS has the following error when I run sudo netplan try:

An error occurred: 'NetplanApply' object has no attribute 'state'

Reverting.
Job for systemd-networkd.service failed because the control process exited with error code.
See "systemctl status systemd-networkd.service" and "journalctl -xe" for details.
Traceback (most recent call last):
  File "/usr/share/netplan/netplan/cli/commands/try_command.py", line 87, in command_try
    NetplanApply().command_apply(run_generate=True, sync=True, exit_on_error=False, state_dir=self.state)
  File "/usr/share/netplan/netplan/cli/commands/apply.py", line 199, in command_apply
    if self.state:
AttributeError: 'NetplanApply' object has no attribute 'state'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/sbin/netplan", line 23, in <module>
    netplan.main()
  File "/usr/share/netplan/netplan/cli/core.py", line 50, in main
    self.run_command()
  File "/usr/share/netplan/netplan/cli/utils.py", line 310, in run_command
    self.func()
  File "/usr/share/netplan/netplan/cli/commands/try_command.py", line 69, in run
    self.run_command()
  File "/usr/share/netplan/netplan/cli/utils.py", line 310, in run_command
    self.func()
  File "/usr/share/netplan/netplan/cli/commands/try_command.py", line 98, in command_try
    self.revert()
  File "/usr/share/netplan/netplan/cli/commands/try_command.py", line 127, in revert
    NetplanApply().command_apply(run_generate=False, sync=True, exit_on_error=False, state_dir=tempdir)
  File "/usr/share/netplan/netplan/cli/commands/apply.py", line 249, in command_apply
    utils.systemctl_networkd('start', sync=True, extra_services=netplan_wpa + netplan_ovs)
  File "/usr/share/netplan/netplan/cli/utils.py", line 177, in systemctl_networkd
    subprocess.check_call(command)
  File "/usr/lib/python3.8/subprocess.py", line 364, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['systemctl', 'start', 'systemd-networkd.service', 'netplan-ovs-cleanup.service']' returned non-zero exit status 1.

I initially thought I made a mistake when I made a small change to /etc/netplan/01-netcfg.yaml but have reverted to the original and the error is still there.

How can I solve this?