@dylan It is hard to believe that this is the reason, because the standard value for sys.path is ['', '/flash', '/flash/lib']. Since main.py resides in /flash, any code to be imported may reside at that place too, like also in /flash/lib or the actual directory (frisdt entry). The latter may be the a cause, if you have multiple copies of your code, good and bad ones, on the file system.