sebastiangohhy
I just happened to make a log system for a project I am working on last night.
I have a global text variable called Log.
at every point in the event sheet where I want to add something to the log I do a "System > Add to Global variable Log" and add NewLine & "whatever text to add"
Then at the end you can do what ever you want with the results: display it, save it, send it to a database, etc