activity: DOMException in element.removeChild

[adbre]

I'm using knockout.activity.js in Durandal with cached views and when opening a multi-instance view the second time a DOMException was thrown in the element.removeChild call, because activityIndicator is not a child to element.

I do not fully understand why this happens though.

My work around is available in adbre/KoLite#1

Because I feel it to be a work around I did not want to propose a pull request to this repository but rather ask for suggestions to why this might happen.