"Activate Features" "The object has been updated by another user since it was last fetched"

I created a Feature Receiver to assign an Event Receiver to various content types. This was working fine. However, after a small update to the code, the package would no longer deploy and failed with the following message:

Error occurred in deployment step 'Activate Features': The object has been updated by another user since it was last fetched.

I discovered the problem was caused because I:

1. Assigned the Event Receiver to a base content type (CT 1).



2. Immediately after attempted to add the Event Receiver to a content type (CT 2) derived from the base content type (CT 1)

To solve the issue, I did not do step (1) above and just did step (2).