"(400) Bad Request" error message (4321989)

The error message below is encountered when migrating content to SharePoint Online (SPO):

Exception: The remote server returned an error: (400) Bad Request.
   at Microsoft.WindowsAzure.Storage.Core.Executor.Executor.ExecuteSync[T](RESTCommand`1 cmd, IRetryPolicy policy, OperationContext operationContext)
   at Microsoft.WindowsAzure.Storage.Blob.CloudBlobContainer.CreateIfNotExists(BlobContainerPublicAccessType accessType, BlobRequestOptions requestOptions, OperationContext operationContext)
   at Metalogix.Azure.ConsoleProcessor.AzureContainerManager.CreateContainerIfNotExists(String storageConnectionString, String containerName, BlobAccessPermissions permissions) Error: The remote server returned an error: (400) Bad Request.
   at Microsoft.WindowsAzure.Storage.Core.Executor.Executor.ExecuteSync[T](RESTCommand`1 cmd, IRetryPolicy policy, OperationContext operationContext)
   at Microsoft.WindowsAzure.Storage.Blob.CloudBlobContainer.CreateIfNotExists(BlobContainerPublicAccessType accessType, BlobRequestOptions requestOptions, OperationContext operationContext)
   at Metalogix.Azure.ConsoleProcessor.AzureContainerManager.CreateContainerIfNotExists(String storageConnectionString, String containerName, BlobAccessPermissions permissions)
Stack: at Metalogix.Azure.Blob.Manager.AzureContainerInstance.CreateContainer(String containerName, BlobAccessPermissions permissions)
   at Metalogix.Azure.Blob.Manager.AzureContainerInstance.GetBlobContainer()
   at Metalogix.Office365.AzureMigrationHelper.Upload()
   at Metalogix.Office365.BatchManifestJob.ProcessManifestItems()

Type: System.Exception

HResult:-2146233088

The issue generally occurs when an incorrect container and/or account name for Azure is used. A container name must be a valid DNS name, conforming to the following naming rules:

• Container names must start with a letter or number, and can contain only letters, numbers, and the dash (-) character.
• Every dash (-) character must be immediately preceded and followed by a letter or number; consecutive dashes are not permitted in container names.
• All letters in a container name must be lowercase.
• Container names must be from 3 through 63 characters long.

For additional information, please click here.

To resolve the issue, please do the following:

1. Open the C:\ProgramData\Metalogix\Environmentalsetting.xml file using any text editor such as Notepad.
2. Check the "AccountName" value in the following key:

   <XmlableEntry>
    <Key>UploadManagerAzureStorageConnectionString</Key>
    <Value>DefaultEndpointsProtocol=https;AccountName=johndoe;AccountKey=pnl7TvOJETTnr6Pheodq2DnF0piOozE BIUdVs2hrr8+l4Jzk2PXqdK0gBEz2qESzkr1c2JVQYJZooQe26pd2AA==</Value>
   </XmlableEntry>
   

3. Make sure it complies with the rules mentioned above, then save the file.

Otherwise, create a new storage container with a valid name, then use it for the migration.