In short, the Arduino IDE won't compile a sketch for the Teensy 3.6. It gives the error:

exec: "A:\\arduino-1.8.5\\hardware\\teensy/../tools/teensy_post_compile": file does not exist
Error compiling for board Teensy 3.6.

What I have tried

-Re-installing teensyduino (And yes, I have it installed, along with a compatible Arduino IDE (version 1.8.5))

-completely wiping the IDE and re-installing

-using a different USB cable

Other information

The OS I'm using is Windows 10

A broken Teensy is not out of the question, as I have been doing some soldering on it and I may have slipped or something, although I don't think that's the problem

Thanks in advance.

  • are you running the IDE from a floppy disk? .... A: is the disk name for the floppy disk
    – jsotola
    May 24, 2018 at 18:54
  • It's my USB stick, I assigned it the letter A: so that it's easy to remember
    – Jachdich
    May 24, 2018 at 20:09
  • Also so other programs that reference it (e.g. my python programs) don't have to be changed on the whim of windows
    – Jachdich
    May 24, 2018 at 20:10

1 Answer 1


I found a fix, it's not elegant or easy to use, but it works.

Steps to take

-Install a fresh version of teensyduino

-Make a copy of [arduino directory]/hardware/tools and save it anywhere as a backup (sometimes weird, buggy things happen)

-Make a copy of teensy.exe from the tools folder, and put it in the same directory as arduino.exe

-every time you run arduino.exe (don't double-click on a .ino file), first start teensy.exe and everything should work.

Sometimes, the tools directory gets deleted (It just seems a bit buggy), if that happens copy the backup and paste it where it should be ([arduino directory]/hardware/tools)

Also occasionally teensy.exe gets deleted, so make sure to have a backup of that as well.

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