Trying to understand the Release Process with Milestones

Here's my goal:
I want to control the release of a project so that only certain WBSs can accumulate costs once certain milestones are reached. I want to block people from confirming activities out of order.

I created a project with the following activities:

Kick Off (milestone) -> Design -> Approve (stop milestone)

The design activity is where we will plan work and charge time.

I released the Kick Off activity only, leaving the Design & Approve activities in the CRTD status

It has it's own WBS, so my project looks like this:

• Project (top WBS) PREL
  • Kick Off activity REL
    
  • Design WBS CRTD
    • Design Activity CRTD
  • Approve activity CRTD
    

When I final confirm the Kick Off activity with CN25, the system reports an error:

"CN699 One or more than one activity was not released. See log"

The Kick Off activity gets status "FKTF - Error when processing function". There is no way I can find to view a log to see what happened. After googling around it seems like the release failed because my Design WBS is not released, however releasing this WBS also releases the Design Activity!

Questions:

1. What am I missing? How is this milestone release function meant to be used?
2. If I cannot automatically release an activity in a WBS that is not released, how do you release the WBS only? Why can I release an activity manually in project builder (giving the WBS PREL) , but not automatically with a milestone?
3. Where is the log mentioned in the CN699 error?
4. How do you un-release something? In case it was released by mistake, I want to unrelease it so no charges are made.