Why you can't edit iCal feed events (and what to do instead)

You can use inbound iCalendar feeds to receive synced events from other calendars (like Google, Outlook, or Apple). These feeds look like sub-calendars in your Teamup calendar, but they have a lock icon indicating that all events on the feed are read-only. You can view these feed events, but you can't edit them. 

Why you can't edit inbound feed events

An iCalendar feed is a one-way synchronization, which creates limitations on what you can do with feed events. 

Edits result in conflicting events

An inbound feed sends events from the source calendar (e.g. Google) to the receiving calendar (Teamup). But you can't send event changes back the other direction; the sync is only one-way.

If you were to edit a feed event in the receiving calendar, this change wouldn't be reflected in the source calendar, resulting in conflicting versions of the event. 

Edits get overwritten by the feed

The source calendar periodically refreshes the feed, sending data to the receiving calendar to keep the sync updated. Any edits you did make to feed events in the receiving calendar (Teamup) would be overwritten when the feed refreshes. You would lose any changes that you'd made to the feed events. 

How to work with feed events

A good option is to duplicate a feed event to another sub-calendar. Then you can make  changes to duplicated event as needed.

To duplicate an event, right click on an iCalendar feed event and choose Duplicate from the context menu, then choose the sub-calendar where you want to the duplicated feed event.