Hello,
All the functions from arduino show up as errors.
Most of them say "identifier "Serial/PinMode/.." is undefined
Some such as attachInterupt show up with the error "expression preceding parentheses of apparent call must have (pointer-to-) function type"

The sketch compiles and gets uploaded fine, but the errors really distract me when I'm trying to solve other problems.
How can I solve the problem?

Thanks

Hello,
I was using Arduino 1.6.1, with nano.
Switching boards didn't solve it, so I changed the version to 1.0.5 and the problem was solved.
After that I removed 1.6.1 and updated to 1.6.3.
The errors are gone now.

Thank you for your time! (I should have known I had to try this first, but I'm glad it's solved now )

I have some similar errors (compiling just fine) using timer interrupt code for arduino due ide 1.6.7.

void setup {
    pmc_enable_periph_clk();
    TC_Configure(, channel, | | );
    TC_SetRC(TC2, channel, timexyz);
    TC_Start(TC2, channel);
    TC2->TC_CHANNEL[channel].TC_IER = ;
    TC2->TC_CHANNEL[channel].TC_IDR = ~TC_IER_CPCS;
();
}

[...]

void TC5_Handler() {
    TC_GetStatus(, 2);
    check_buttons();
}