In order to solve the issue, amend the Veeam ONE Monitor and Veeam ONE Reporter service credentials:
1. Open Services snap-in on the Veeam ONE server;
2. Find the Veeam ONE Monitor Server service and open the properties;
3. Navigate to the Log On tab;
4. Select This account option and specify your credentials using the Domain\Username prefix;
NOTE: The service account must have Local Administrator permissions.
5. Restart the service to apply the changes;
6. Perform the same steps for Veeam ONE Reporter Server service;
7. Install the Update.