Hello,
I’m also having this very same issue ever since a few days ago, after I migrated my site from local to a shared hosting server. Apparently my site’s issue is due to a path that did not update during the migration process.
The directory supplied in Backup Location cannot be used as a valid directory. The directory /srv/http/wp-content/uploads/ithemes-security/backups could not be created due to an unknown error. This could be due to a permissions issue.
Now, I can’t find where to correct this path anywhere in the settings.
Hoping for a reply,
Javier