swirl - Statistical Inference - Coursera credit returns endless error (loop)

[Roi-Shir-Dishon]

once the lesson is completed, the question "| Would you like to receive credit for completing this course on Coursera.org?" is presented with 2 options:

1: No
2: Yes

whatever you chose, returns an error (and an endless loop):

1: No
2: Yes

Selection: 1
argument is of length zero

| Keep trying!

|

1: Yes
2: No

Selection: 1
argument is of length zero

| Not quite! Try again.

[Roi-Shir-Dishon]

other options doesn't work too:

Selection: 0
argument is of length zero

| You almost had it, but not quite. Try again.

|

1: No
2: Yes

Selection: skip()
Enter an item from the menu, or 0 to exit
Selection: 0
argument is of length zero

| Give it another try.

|

1: No
2: Yes

Selection:

**so far, the only thing that terminate the promt is the ESC button that throw you out of Swirl