Post JSON to web in excel vba
JSON can be very sensitive to how it's formatted, so I would make sure everything is quoted properly before it is sent. I would recommend splitting Body into a separate variable and debugging the value with http://jsonformatter.curiousconcept.com/ before sending.
Dim Body As StringBody = "{""mType"":""OPEN_SYSTEM_TRADE"",""systemOwnerId"":10}"' Set breakpoint here, get the Body value, and check with JSON validatoroHttp.Send BodyI ran into many similar issues when working with Salesforce's REST API and combined my work into a library that may be useful to you: https://github.com/VBA-tools/VBA-Web. Using this library, your example would look like:
Dim Body As New DictionaryBody.Add "mType", "OPEN_SYSTEM_TRADE"Body.Add "systemOwnerId", 10Dim Client As New WebClientDim Response As WebResponseSet Response = Client.PostJson("somewebsite.com", Body)Worksheets("Open1").Range("A1").Value = Response.Content