# Messages and Warnings

FluidFlow provides a large number of Error Messages, Calculation Warnings, Component Warnings and Engineering Hints. From the standpoint of the user: errors, warnings and hints fall into 3 classifications. The first classification are showstoppers, i.e., you cannot solve a network or cannot utilize the results from a solution if a build error or a critical solver error has occurred. The second classification contain warnings arising from the calculation. It is necessary for you, the user, to evaluate the impact of this type of warning. In most cases it is not appropriate to ignore these warnings, at least not without understanding the design, operating, and safety implications. The third classification contain warnings and engineering hints specific to each component type. All error, warning, and hint messages are displayed in a single list contained on the Messages page of the Data Palette as shown below. In this example there is a warning showing that the pipe length connecting orifice (2) to the open pipe (3) is shorter than the elevation difference between the two connecting nodes. This warning belongs to the pipe and falls into the third classification as defined above. In this case there is likely to be a data entry error either in the pipe length or the elevation of one or both of the connecting nodes. The flowsheet and items in the error, warning and hint list (messages list) are linked. This means that if you click on an item in the list, then the component is highlighted in the flowsheet. The converse is also true. This means that you can use the list to move through all warnings after a calculation. It is good practice to get into the habit of viewing all items in this list each time the calculation button has been pressed. It is useful to be aware of the processes invoked each time the Calculate button is pressed. ▪First, all items in the messages list are cleared. i.e., all previous warnings, errors and hints are cleared. ▪The application then checks for network build errors and inconsistencies. If any errors are found then the calculation cannot proceed. ▪Assuming the network has been connected correctly, then the calculation solver is called. As the iterative solution proceeds any critical errors that occur are immediately forced into the messages list. In all solver processing, error messages should NOT occur. If an error or warning occurs at this time it will be marked as critical and you will be asked to contact our email support service. No other warnings or hints will be displayed and you should NOT consider the results to be accurate or representative of the model in operation as entered. ▪If there are no critical errors (should always be the case), after the solver has converged to a solution any individual component warnings or engineering hints are entered automatically into the messages list. Error, Warning and Hint Messages are saved along with the network and flowsheet information. This means that if you open an existing network from a file, the error, warning and hint messages are an integral part of the file and will be shown immediately in the Messages list.