If you see a red ‘!’ it means you that on that page further data needs to be entered to generate results.
If you see an orange ‘!’ it means data that is not compulsory has not been entered and you may want to check that it is not needed. The orange warning messages can be suppressed.
If your analysis is not generating any results:
A red ‘!’ will appear on the reports tab, when you click in to the Reports page a red banner error message will show describing the issue: