The REST docs for creating Events is incomplete, so I tried to figure it out with some trial and error, but I hit a brick well.
I created an event manually and then fetched it with the REST API to get a list of the Event properties, then tried using that to create a new event. After several iterations of using all of the properties, none of them, some of them, and some other variations (like passing Title instead of EventTitle), I only ever received this error message.
"An unexpected error prevented your requested action from completing. The error has been logged for the administrator to review."
When I reviewed the Admin Console integration logs I found this stack trace, which didn't do much to help me track down the issue.
System.NullReferenceException: Object reference not set to an instance of an object.
at Telligent.Evolution.Calendar.Plugins.RestApi.Implementation.Events.EventCreateRequest..ctor(IRestRequest request)
at Telligent.Evolution.Calendar.Plugins.RestApi.CalendarRouteRegistrar.<>c.(IRestRequest )
at Telligent.Evolution.Rest.Framework.Infrastructure.RestPluginHttpHandler.ProcessRequest(HttpContextBase context, HttpResponse httpResponse)
Here is an example request that I sent to the server. I confirmed that Calendar ID 1 does exist.
POST /api.ashx/v2/calendars/1/events.json HTTP/1.1
Here is a readable version of the params and values.
EventTitle: Happy Day!
EventDescription: <p>This is an event!</p><div style=\clear:both;\></div>
Unfortunately, there is an internal error that prevents this API from working. I've logged the bug for review:
The only work-around would be to create a widget that can handle the same request and calling it through the scripted REST endpoint: community.telligent.com/.../post-scripting-rest-endpoint
'#106060 Cannot create event via REST' has been completed for 2/2018 - February Emergency Hotfix affecting 10.1.