I have been searching the web for a solution to this issue with no luck. I have a team project in Visual Studio Team Services (VSTS) using an inherited copy of the scrum process template so that I can make modifications to the individual work item templates.
Any time I attempted to import a modified WIT I received a very vague error which appears to simply quote the Microsoft.TeamFoundation.WorkItemTracking.Server.ProvisioningImportEventsCallback namespace or class.
In an attempt to keep this simple I am simply exporting the product backlog item WIT and then immediately re-importing it to ensure that the error is not related to a change I have made. I have also renamed what I am importing in case there was an issue overwriting the existing WIT and that made no difference. I have been able to do this with TFS 2010 with Visual Studio 2013 but in both VS 2013 and 2015 with VSTS I am not able to import any WIT modifications.
While in TFS you can use witadmin.exe (or the old API) to update work items, this does not with VSTS.
If you are on the inherited template model then your only option is to use the Web Interface to edit the work items. There is some API's for working with this in the new Rest API's: https://www.visualstudio.com/en-us/docs/integrate/api/overview
The tip from Edit a WIT definition file article:
Tip: With witadmin, you can import and export definition files. Other
tools you can use include the Process editor, available for TFS 2015
and earlier versions, and which you install from TFS Power Tools. Or,
you can use the TFS Team Project Manager, a community resource project
available on CodePlex.
The witadmin is not available for VSTS and as MrHinsh said that you can edit work items on Web Access.
Regarding APIs’:
Get process template:
Request type: Get
URL: https://[xxx].visualstudio.com/_api/_process/GetProcesses?__v=5
Create work item type:
Request type: Post
URL: https://[xxx].visualstudio.com/_apis/work/processDefinitions/[inherited process template id (refer to get process template]/workItemTypes?api-version=3.0-preview.1
Body (application/json):
{
"name":"WITCustom5",
"description":"des",
"color":"D3D3D3",
"isDisabled":false
}
Add field to inherited process template:
Request type: Post
URL: https://[xxx].visualstudio.com/_apis/work/processDefinitions/[inherited process template id]/fields?api-version=3.0-preview.1
Body (application/json)
{
"name":"f1",
"type":"string",
"description":""
}
Add field to work item type:
Request type: Post
URL: https://starain.visualstudio.com/_apis/work/processDefinitions/[inherited process template id]/workItemTypes/[work item type id (refer to Create work item type)]/fields?api-version=3.0-preview.1
Body (application/json):
{
"id":"[field id (refer to Add field to inherited process template)",
"name":"[field name]",
"type":"string",
"rules":[
{
"rule":"$required",
"value":null
}
],
"description":""
}
On the other hand, REST API for customization is simple and in preview. More information, you can refer to VSTS Process Customization futures.