In course LearnHTML&CSS Part1 1/9(the beginning of this course)
when I type my name "Anna" between
<h1> and </h1>, then press run
(write line 10:
<h1> Anna </h1>)
there is an error that "s.DeferredSignal is not a function."
I don't understand it and cannot continue my job TAT
Please give me some help.