@jeffb no, no, no don't edit the files!
There are 2 causes for the error that has plagued M5Stack since the beginning.
1st - driver issue. the driver is temperamental in osx and often does not work.
2nd and most important as its the biggest issue. The factory USB leads are often faulty and or just rubbish. Always use a high quality USB sync/data lead. something over the £10/$10 price range and never fold the lead, always roll it.
I had this issue when I first started as I have only OSX.
Also, when you install any new board or library in arduino, ALWAYS close arduino and restart it!
