Illegal Choice error when javascript is disabled

I can confirm this for 7.x-1.4

An illegal choice has been detected. Please contact the site administrator.

Mind having a peek at the HTML to see what might be causing the issue with this modules markup output?

Tested. Quite right.
This is likely due to adding #1510294: Support for duplicate paths within the same menu

The comment above that somewhat obtuse function is "Allows PHP array processing of multiple select options with the same value." I overrode the normal option output function, which might have landed us with this error.

I do take no-JS support fairly seriously, so I'm almost inclined to call this major.

This is something related to CTools and not this module.

My module https://www.drupal.org/project/better_jump_menu provides the fix for this.

And for people asking why there are two modules doing less or more the same... here's my answer:
When I did this module, I didn't find know the existence of this module, and as it seems to be unmaintained, I decided to publish it.
I wrote to the maintainer about it and if he reads me, I'm absolutely open to merge my or your change in one of the two module, contact me and we'll decide what to do together.

Thanks.

Indeed this problem comes to a solution by changing the function ctools_jump_menu in jump-menu.inc in (ctools > includes).

In my case, I added the lines

  if (isset($form_state['input']['jump'])) {
    $form['jump']['#value'] = $form_state['input']['jump'];
  }

before "return $form;" and now it works.

But I'm not shure if this is a bug in ctools or a special request of this module. So the maintainer should decide if we should file a bug report against the ctools module or if there is a way to enhance this module. In my case, I made a copy of jump-menu.inc, renamed the functions and included the new file into this module ...