Reimplementation After Migration from TFS 2015 (hosted XML process) to Azure DevOps Services

[erelado]

We are currently using the legacy extension for our TFS 2015. We performed a dry-run migration into Azure DevOps Services, which, among other things, required us to remove the MultiValue Controls from the WITs *.xml files (under WorkItem Tracking/TypeDefinitions) because it is not applicable in Azure DevOps Services (using migrator validate command).

After the migration succeeded, it appears that the only way to edit those hosted XML processes is to export, then edit, then import a modified *.zip file of the entire process. Using the current extension version, I would like to reimplement the MultiValue Control fields. However, I cannot locate documentation on how to insert it into a hosted XML file.

Readding the line from the legacy extension (for TFS 2015) results in the same error as prior to the migration: <Control FieldName="<NAME>" Type="MultiValueControl" Label="<NAME>:" LabelPosition="Left" />

Message	File name	Line number	Help link
TF402582: Work item type Design contains custom control MultiValueControl which is not supported.	WorkItem Tracking\TypeDefinitions\Design.xml	736	https://go.microsoft.com/fwlink?LinkID=534697

EDIT

The required documentation can be found here. That being said, when trying to re-import the .xml file using witadmin, I get the following error:

VS1640129: The collection you are targeting uses inheritance process model. This operation is not allowed on an inheritance process model based collection. Please refer to https://go.microsoft.com/fwlink/?linkid=849010 or contact your system administrator for help.