Missing or Corrupt Core Libraries / Files (EEPROM, AVR)?

Good evening

Having a few problems and wondering if you guys can help. Whenever I try to write scrips that need to use EEPROM / AVR stuff I get lots of ERROR messages like:

Arduino: 1.6.8 Hourly Build 2016/02/24 06:12 (Mac OS X), Board: “Arduino 101”

In file included from /Users/Stewart/Documents/Arduino/sketch_feb28h/sketch_feb28h.ino:1:0:
/Users/Stewart/Documents/Arduino/libraries/EEPROMEx/EEPROMex.h:29:24: fatal error: avr/eeprom.h: No such file or directory
#include <avr/eeprom.h>

Or the same but missing avr/io.h and so on. It appears that some of the Standard Libraries are missing and I’m having trouble getting hold of / installing them.

Please would some one be able to help but be gentle with me as I’m kinda new to the Arduino.

Many thanks,


Try to reinstall the IDE.

Maybe don't use an hourly build but a more stable version. I think general consensus is to use 1.6.5 (or older) as some people have experienced problems with 1.6.6 or 1.6.7; I however don't have encountered problems with 1.6.6 on Windows8 64 bit.