If the Project Status Items reports a large processing total error this means the final value of the Final Total Error was greater than the threshold listed on the Project Review Settings Dialog.
A large total error indicates the project data (e.g. point positions) fed into processing do not form a consistent model. That is, no solution could be found that agreed with all the given the mark locations, camera positions, camera calibration parameters, etc. Start by addressing any other warnings displayed on the Project Review Pane, as weakness in any inputs will increase the total error.