I'm following a tutorial in 'The Power of Expressions' about optimisation in expressions and I created the following three lines (as directed by the text in the book):
var Variable1 = 10;
let Variable2 = 10;
const Variable3 = 10;
After Effects has disabled this expression because of a syntax error on line 2, which it claims is missing an expected ';'. I've checked and rechecked the text in the book but I can't see a difference.