Why can’t I change the quotation on a contracted cost sheet?

When the cost sheet status becomes Contracted, the quotation is part of the contract, so the Construction Quotation field in the edit form becomes read-only and can’t be changed or removed. This keeps the cost sheet consistent with its linked contract and quotation.

A message at the top of the edit form explains how your changes apply, based on the contract status:

Contract status	Message
Active, Closed, or Cancelled	Updates to the cost sheet will only impact the budgeting of the project; they will not impact the related contract or quotation.
Draft or Issued	Updates to the cost sheet will reflect in related contract; By activating the contract, changes in cost sheet will only impact project budget!