From Xojo Documentation
Writes msg to the logging mechanism.
On macOS and Linux, it writes to the system logger, which is typically at /var/log. On Windows it writes to the Event Logger, which can be viewed by the Event Viewer.
|On macOS, the following levels do not appear in the log: debug, information, and success. This is an macOS issue.|
For debugging purposes, use System.DebugLog instead.
Use the following class constants when setting the value of the Level parameter in calls to the Log method.
|Level class constants|
For the following example writes your error message with the LogLevelError constant.