traceback.log will be in your working folder. Couple of ways to find your working folder are to look at your icon for launching Creo, right click properties. It's your "start in" folder. Or launch Creo, file open, click the working directory folder and look at the path on the to of the file open dialog.
Traceback.log is a text file you can open with a text editor but you will likely not find any useful info in there. It's generally for submitting to PTC tech support where they can read it and possibly diagnose potential problems.
Steve Williams Pro/E Version 15/16 (Circa 1995/1996)