Unable to deaden opportunity - there are unticked costs

Issue:

When trying to deaden an opportunity you receive a message about unticked costs

Resolution:

You cannot deaden an opportunity if there are costs on it that have been neither invoiced nor written off (ie they are unticked) and still in WIP (work in progress).

Either transfer the costs to another job / phase, or write off the opportunity. You will then be able to deaden it if desired.