You have a control that has a bad expression, or a bad name. Once one of the
calculated controls fails, Access gives up on calculating the subsequent
ones as well.
You probably have text boxes with an expression in their control source,
e.g.:
=Trim([FirstName] & " " & [LastName])
With the report open in design view, right-click this text box and choose
Properties. Make sure the Name of the text box is not the same as the name
of any field. For example, it cannot be called FirstName or LastName in this
example. Access gets confused if the Name is the same as a field but it is
bound to something else.