Azure Migrate Source Validation Failed. Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

Niklas Peter Wulff-Høyer 0 Reputation points
2024-12-17T13:10:20.2666667+00:00

Hi,

Using the azure migrate appliance, I am attempting to perform a discovery of physical servers, which is actually just ~100 VM's running on a non hyperv/vmware platform.

I get the following error message when attempting to validate VM's:

Source Validation Failed

The server 'x.x.x.x' returned an unexpected error. Error code: '-2146233086'

Error details: 'Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index'.

There are no useful recommendations associated with the error. When I attempt to research this issue, i get no results. Only some programming related articles.

Only 30 ish VM's out of 100 are experiencing this error.

I am very confused as to which index is being referenced. We have checked WinRM functionality, port openings, disabled firewalls, tested using local machine credentials, domain admin, joined appliance server to the domain. All vm's are on the same subnet. There are no useful entries in event logs, except security entries containing the credentials defined in the migrate appliance when attempting validation of vm's, but they are simple logon succeded entries.

Some vm's failed validation due to WinRM or credential issues, those have been fixed just fine. We remain at a loss in regards to this Index error.

We have tried using an appliance running on server 2022, and on 2019. All deployed with specs recommended by MS.

Azure Migrate
Azure Migrate
A central hub of Azure cloud migration services and tools to discover, assess, and migrate workloads to the cloud.
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  1. Pavan Minukuri 915 Reputation points Microsoft Vendor
    2024-12-19T23:11:12.7766667+00:00

    Hi Niklas Peter Wulff-Høyer
    The error "Source Validation Failed" with code '-2146233086' and the message "Index was out of range" during the Azure Migrate discovery process likely indicates an issue with how the Azure Migrate appliance is handling VM data.

    Here are some possible causes and troubleshooting steps:

    1. Index Reference Issue: The error suggests the appliance is trying to access a non-existent index in a collection, possibly due to inconsistent processing of VM data.

    WinRM Configuration: Verify that WinRM is properly configured on all affected VMs. Run winrm quickconfig to test its functionality.

    Firewall and Network Settings: Ensure there are no firewall or network issues blocking communication between the Azure Migrate appliance and the VMs. Check that ports 5985 (for WinRM) and 22 (for SSH) are open.

    Credentials Verification: Confirm that the credentials used for the failed VMs have the correct permissions and are properly configured in the Azure Migrate appliance.

    Event Logs: Enable detailed logging to capture more information during validation attempts, especially for authentication or connectivity errors.

    Azure Migrate Appliance Health: Check the appliance's health in the Azure portal to ensure all agents are working correctly and there are no connectivity issues.

    1. Retry Validation: After making adjustments, try validating the affected VMs individually to pinpoint which VM configurations may be causing the issue.

    If you required anything please let us know.


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