Interesting. This is indeed a bug in the sizeof macro. No one noticed it all the time because it only happens with structs that are never used in the script.

This bug will be fixed in the next update. Until then, use this workaround when your script accesses no TICK element, but still needs the TICK size:

function main()
{
TICK* t; t->time = 0;
printf("\nsizeof(TICK)=%d\n", sizeof(TICK));
}