Open a command prompt and change folder to the Forefront Program files folder. By default this should be "C:\Program Files (x86)\Microsoft Forefront Protection for Exchange Server"
Next run the following command:
fsctraceformat.exe .\data\programlog.etl –p .\data\tmf –o .\data\programlog.txt
The log file is created in data subfolder and you can open it with any text editor like notepad.