Encountering errors while attempting to access a virtual machine (VM) from the host in the context of BDRSuite Backup Server. This issue can occur due to various causes related to the Hyper-V environment and access protocols.

Cause 1: Hyper-V Virtual Machine Management Service Not Running/Enabled

Cause: The Hyper-V Virtual Machine Management Service is not running or enabled on the owner node machine.

Solution: Ensure that the Hyper-V Virtual Machine Management Service is operational by following these steps:

1. Open the "services.msc" application on the Hyper-V host machine.

2. Locate the "Hyper-V Virtual Machine Management Service" and check its status.

3. If the service is stopped or disabled, start it to enable proper backup operations.

Additional Steps for Windows Management Instrumentation (WMI) Access:

Case 1: Ensure that your firewall doesn't block WMI functions. Add a rule to your inbound firewall rules:

a. Navigate to Control Panel > System and Security > Windows Firewall > Advanced Settings.

b. In "Windows Firewall with Advanced Security," go to Inbound Rules.

 c. Create a new rule using the Predefined option.

 d. Select 'Windows Management Instrumentation' rule and enable it.

Case 2: Verify that the "Windows Management Instrumentation" service is running on the target machine.

Case 3: For NAT environments, allow the WMI port in the NAT firewall:

1. If WMI uses a static port, add that port to the NAT firewall.
   
2. If WMI uses a dynamic port, add the port range 1024 to 65535 to the NAT firewall.
   

Steps to Convert WMI Port from Dynamic to Static:

1. Open Run and type 'dcomcnfg'.

2. Navigate to My Computer > DCOM Config > Windows Management and Instrumentation.

3. Access properties and select the Endpoint tab.

4. Click the Properties button for Connection-oriented TCP/IP.

5. Set a static endpoint and specify the port.

Confirmation Test:

​Perform a pre-test using the WBEM utility:

1. Open "wbemtest" on your server/client machine.

2. Provide the Target hostname/IP in the namespace text box: \IP\root\cimv2.

3. Provide the username and password (not required for local machines).

4. Click "Connect" and ensure a successful connection.

Cause 2: VM Deleted/Removed on Target Hyper-V Server

Cause: The VM configured for backup is deleted/removed on the target Hyper-V Server.

Solution: To address this issue:

1. Login to the BDRSuite Backup Server.

2. Navigate to Backup > List Backup Jobs page.

3. Under the 'Actions' column, click the 'Edit' icon for the corresponding backup job.

4. Remove the deleted/removed VM from the backup configuration and update the settings.

5. Deleted VM's backup data will be retained based on the configured retention policy.