I spent hours to try to find a solution to fix this error at compilation.
My code don’t have any problem, just the things showed up after upgrading arduino (win XP).
What I did at the end was to add dummy variable to the code and it worked. Try to add 1, 2, 3 , 4 and it worked!!
byte y1 = 0; byte y2 =0; byte y3 =0; byte y4=0;