Steps to reproduce

Update a work item field with impersonation enabled (i.e. .impersonate=onBehalfOfInitiator)

A simple update ( self["Custom.CustomField"] = 10) or any other update will trigger an error.

Version 1.0.1

Expected behavior

WorkItem should be updated successfully

Actual behavior

Update fails with the message: "Remove requires Value to be null."

Diagnostic logs

Running it locally and adding some additional debug info:

[2021-02-06 16:11:35Z] [{"Method":"PATCH","Uri":"/_apis/wit/workItems/160536?bypassRules=True&suppressNotifications=False&api-version=5.0-preview.3","Headers":{"Content-Type":"application/json-patch+json"},"Body":"[{\"op\":5,\"path\":\"/rev\",\"from\":null,\"value\":11},{\"op\":2,\"path\":\"/fields/Custom.GTRMScore\",\"from\":null,\"value\":80},{\"op\":1,\"path\":\"/fields/System.ChangedBy\",\"from\":null,\"value\":\"George Roberts\"}]"}] [2021-02-06 16:11:35Z] [{"Code":400,"Headers":{"Content-Type":"application/json; charset=utf-8"},"Body":"{\"count\":1,\"value\":{\"Message\":\"Remove requires Value to be null.\"}}"}] [2021-02-06 16:11:35Z] Save failed: {"count":1,"value":{"Message":"Remove requires Value to be null."}} [2021-02-06 16:11:35Z] Changes saved to Azure DevOps (mode Batch): 0 created, 1 updated. [2021-02-06 16:11:35Z] Rule returned '' [2021-02-06 16:11:35Z] Succeeded

First log line is the JsonPatchDocument info for the update.

Second log line is the actual response with the response code.

Environment

Happens both locally and in Azure Functions.