Restore to AWS EC2 Fails with: "ClientError: Unknown OS / Missing OS files."

Direct recovery to AWS EC2 without using the helper appliance works successfully and does not encounter this issue.

Note: This issue does not affect the restore of AWS EC2-native VMs. For those EC2-native VMs, it is recommended to use the helper appliance.

For Veeam Backup & Replication 13.0.x

In Veeam Backup & Replication 13.0.x (e.g., 13.0 and 13.0.1), disable the option "Use the helper appliance" in the restore wizard.

Reference: Restoring to Amazon EC2 > Step 8. Configure Helper Appliance

Note: A solution to resolve the root issue will be included in a future Veeam Backup & Replication release.

For Veeam Backup & Replication 12.3.x

In Veeam Backup & Replication v12.3.x (e.g., 12.3, 12.3.1, and 12.3.2), the option for "Use the helper appliance" during the restore process is greyed out and cannot be disabled. To make the option selectable, create the following registry value on the Veeam Backup Server. After configuring the registry value, the “Use helper appliance” option should be disabled when restoring non-AWS EC2-native VMs to AWS EC2.

Key Location: HKLM\SOFTWARE\Veeam\Veeam Backup and Replicationxxx
Value Name: PublicCloudRestoreEnableApplianceSelection
Value Type: DWORD (32-Bit) Value
Value Data: 1

Note: The Veeam Backup & Replication Console must be closed and reopened for the setting to take effect.

PowerShell command to set registry value: