won't update – fs_unavailable

I have the same problem:
https://wordpress.org/support/topic/wont-update-fs_unavailable
I opened a new ticket because there is no answer to the old one, no solution is offered.

In my wordpress I have 1 plugin that needs updating.
When Automatic Updater runs at night, it sends me the following email

WordPress site: http://xxxxx.com
The following plugins were successfully updated:
 * SUCCESS:

UPDATE LOG
==========

  Updating plugin:
  The plugin is at the latest version.
  Error: [fs_unavailable] Could not access filesystem.
It doesn't update the plugin.

How do I fix the ‘fs_unavailable’ issue?

1. The notice “success” is not correct.
2. If you manually update wordpress it works.
3. I have plugin “Wordfence” in use.
   May this be the cause for it?

Thanks in advance.

https://wordpress.org/plugins/automatic-updater/