Problems migrating from on-prem SP 2010 using new SPO Migration API.

I have an on-prem SP 2010 server and I’m trying to migrate data to SharePoint Online using the new API. When I run the ConvertTo-SPOMigrationTargetedPackage command the following error shows in the ConvertMigrationPackage log:

Warning Source XML file C:\package\LookupListMap.xml was not found

The last part of the log is this:

7/10/2015 4:20:27 PM Information Looking up Folder object ‘185dc0fb-f354-4abc-a6a8-001c85c1a59e’ at ”
7/10/2015 4:20:27 PM Error Fatal Exception found: Value cannot be null.
Parameter name: uriString –

The problem is that the XML file is not created after running “ConvertTo-SPOMigrationTargetedPackage” on the SP Site Export. Does anyone know why? Is there a manual way that I can do this?

User Guide that I am referencing for the SPO Migration API.

https://technet.microsoft.com/en-us/library/mt203923.aspx

Here are the steps that I’m taking:

Step 1 Export the SP document library:

Export-SPWeb -Identity <On-prem site URL> -ItemUrl <Document Library path> -Path “C:\Users\username\desktop\sp-export” -NoFileCompression -IncludeVersions All -IncludeUserSecurity

Step 2 Create new content package

ConvertTo-SPOMigrationTargetedPackage -SourceFilesPath $sourceFiles -SourcePackagePath $sourcePackage -OutputPackagePath $targetPackage -TargetWebUrl $targetWeb -TargetDocumentLibraryPath $targetDocLib -Credentials $creds

FYI: The source files path and the package path are the same. The XML file are in the same directory as the DAT files that are created from Export-SPWeb.