I have been using an ATTiny85 using the ATTiny board manager at http://drazzy.com/package_drazzy...
It I select Board -> ATTiny25/45/85 this works fine.
Then I try changing to the ATTiny261/461/861 and I get this error :
sketch\Solar_3.ino.cpp:1:21: fatal error: Arduino.h: No such file or directory
But if I change it again to ATTiny461/861(Optiboot) it then compiles fine.
Any ideas why I get the error in the one I want to use ?