Messages of running tasks appear in the log window.
Additionally, warning and error messages may pop up a small window to alert the user:
Warning dialogs include a check-box, which allows subsequent occurrences of the same warning to be ignored, so that no further user interaction is needed. However, all occurrences are still written to the log. The warning is re-enabled next time the task is run.
Note that warnings can also be suppressed via command line switches as discussed in the taskmain package.