0x8004230F or Error: VSSControl: -2147212529 (VSS_E ...
https://www.veeam.com/kb178526.06.2013 · 0x8004230F translates to the VSS error “VSS_E_UNEXPECTED_PROVIDER_ERROR”, which generally means that the backup process could not initialize due to a third party VSS Provider component installed on the system. You can verify this by opening an elevated CMD prompt and typing VSSADMIN LIST PROVIDERS on the guest which is failing to backup.