After opening this file I get this message when I hit the upload arrow: Arduino: 1.8.8 (Windows 10), Board: “Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)”
c:\users\john\downloads\arduino-1.8.8-windows\arduino-1.8.8\hardware\tools\avr\bin…/lib/gcc/avr/5.4.0/…/…/…/…/avr/bin/ar.exe: unable to rename ‘core\core.a’; reason: File exists
exit status 1
Error compiling for board Arduino/Genuino Mega or Mega 2560.
This report would have more information with
“Show verbose output during compilation”
option enabled in File -> Preferences.
What is causing this error?