There are several different types of error and warning in Junctions. Generally, most of them can be seen at any time by clicking on the Errors button on the main toolbar (this may also be referred to as “Task List”). In Junctions 9, this button will light up orange if there are any warnings in the file, and red if there are any errors. Click on it to show a list of all warnings/errors in the file.
If there are any errors (coloured red), then you cannot run the traffic model.
If there are any warnings (coloured orange), then you can usually run the traffic model, but the warnings will be included at the top of any report that you generate. Many of these warnings are for information only and do not necessarily mean that there is anything wrong with your file.
In a small number of cases, errors are only shown when you try to run the traffic model. This is usually because it is not possible to anticipate the error before attempting the run.