This issue seems to crop up for a lot of people, in a lot of contexts (this is the only instance of it in Arduino land that I'm aware of, but people have encountered analogous errors with a wide variety of software). And like here, it's an issue that occurs for a small portion of systems, but happens every time on impacted systems. Lots of issues closed as "cannot reproduce" - unsurprising, since it seems specific to the small number of impacted systems.It looks like it's something related to the windows console character encoding - but it's unclear why some people have it and other's don't. Are you using unusual language/locale settings by any chance? I saw one intriguing comment from an unrelated java program (some stupid minecrap thing) "If anyone is using Windows 10, be sure to not tick the following in Settings/Region and Language/Administrative Language settings/Change System Language.In there, is a box called: Beta: Use Unicode UTF-8 for Global language support, dont tick this."That setting doesn't seem to keep me from starting Arduino IDE, though.