It can be super useful at times to have a log file viewer application when working on mods, this will give you a live feed of a mods log file including any errors and tm.os.Log outputs without the need to keep refreshing the log file for the mod in a program like Notepad etc.
An useful tool for this is called TailViewerand is completely free, you can open the log file with the program and click on the Follow Tail option and the program will keep up with the generated log file for the mod line by line.