You can change teensyduino versions in the Boards manager. Second icon down on the left edge of main window opens that.
Pull the scroll bar way down and you will find "Teensy by Paul Stoffregen". It should show, by...
I'll holler uncle.
I redid the process (0.58.3 -> 1.57.2) and got no error.
I have no idea what happened, but I am back on 1.57.2 and this time it works.
- Wes, W5ZZO
I installed Beta 3 and everything worked. But I got tired of being nagged about updating my boards, so I reverted to 1.5.7 (awaiting release).
I got this error:
exec:...